Poultry doi: 10.3390/poultry5020030

Authors: Maike Alena Hettmannsperger Isabelle Ruhnke

The manual handling of poultry is an essential part of raising and caring for birds. The different manual catching methods have various impacts on the bird’s welfare and health, the well-being and work satisfaction of the people who are handling the birds, and the economic and logistical requirements of everyone involved. The traditional approach of using the Five Freedoms for investigating animal well-being has been amended with animal-based measures (ABMs) as well as the evaluation of five welfare domains, which consider the subjective response of an animal towards its environment. The assessment of single individual animal welfare parameters without context can be non-specific, only partially informative, or even misleading when considered in isolation. The objective measurement of suitable parameters for the evaluation of the various steps of poultry catching and transport is complex and should be carried out in a differentiated manner. This review summarizes the current knowledge about the manual catching of poultry, with special focus on the upright and inverted handling of chicken and current considerations in Europe. The implementation of consistent, transparent, and traceable central data collection on animal health and welfare at various critical control points of bird transportation would allow systematic evaluation of the multifactorial welfare assessment in the future.

Poultry doi: 10.3390/poultry5020029

Authors: Mayra Carraro Di Gregorio Isabelle Lara Lima Gonçalves Leandro Augusto Calixto Marcos Ferrante Bruna Christina Fernandes Soares Cristiane Soares da Silva Araújo André Tadeu Gotardo Silvana Lima Górniak

The global restriction of antimicrobial growth promoters has intensified the search for alternative strategies to sustain poultry health and productivity. One proposed mechanism underlying the historical efficacy of antibiotic performance enhancers is the modulation of intestinal inflammation. In this context, meloxicam (MLX), a preferential COX-2 inhibitor and non-steroidal anti-inflammatory drug, has emerged as a potential candidate for investigation. However, pharmacokinetic data in broiler chickens remain limited, particularly for practical oral formulations intended for production systems. This study aimed to characterize the pharmacokinetic profile of a novel granulated MLX formulation in male Cobb 500 broiler chickens following single-dose administration. Seventy-two 21-day-old broilers received MLX granulate (19.24% m/m) via oral gavage at 3.6 mg/kg body weight. Plasma samples were collected over 48 h post administration. MLX concentrations were quantified using validated high-performance liquid chromatography, and pharmacokinetic parameters were estimated using nonlinear mixed-effects modelling (NLME). Mean pharmacokinetic parameters included AUC0–∞ of 79.97 μg·h/mL, Cmax of 14.43 μg/mL, and Tmax of 1 h, indicating rapid absorption and substantial systemic exposure. These findings provide novel insights into MLX disposition from the granulated formulation in broilers and provide pharmacokinetic information to support future investigations evaluating its potential biological effects in poultry production systems.

Poultry doi: 10.3390/poultry5020028

Authors: Hsyang-Hsun Chung Ming-Chu Cheng Ya-Mei Chen Kuo-Ping Shen Yi-Yang Lien Shyang-Chwen Sheu Meng-Shiou Lee Suttitas Tongkamsai Hung Su Yi-Lun Tsai

This study aimed to evaluate the potential of Lonicera japonica Flos (LJF) as an alternative agent against Eimeria tenella (E. tenella) in chickens and to conduct phytochemical analysis to obtain compositional insights. Seventy-two one-day-old chickens were allocated to six groups and fed diets supplemented with LJF powder (LJFp) at three concentrations (LJFp-L, LJFp-M, and LJFp-H) or maduramicin (MDM) or two non-supplemented control diets, namely, an infected unmedicated control (IUC) and an uninfected unmedicated control (UUC). Dietary treatments were initiated at chick arrival (Day 0) and continued for 28 days. At 21 days of age, all groups except the UUC group were orally challenged with a field isolate of E. tenella (PT-Te003; 2.0 × 104 oocysts/bird). Anticoccidial efficacy was assessed using the lesion score (LS), oocysts per gram of feces (OPG), relative body weight gain (rBWG), and anticoccidial index (ACI). The results demonstrated that all LJFp treatment groups had significantly reduced cecal OPG and LS (all LJFp treatments: p < 0.05 vs. IUC), indicating the effective suppression of E. tenella replication and intestinal damage. Regarding growth performance, the rBWG values of the LJFp-L and LJFp-M groups were the highest and comparable to those of the UUC group, showing no significant differences. In contrast, the LJFp-H and MDM groups exhibited significantly lower values (p < 0.05). Based on ACI evaluation, all LJFp-treated groups exhibited moderate to partial efficacy (LJFp-L > LJFp-M > LJFp-H), while MDM showed limited effectiveness. A gas chromatography–mass spectrometry (GC-MS) analysis of the LJFp ethanol extract revealed 15 essential oils, 10 organic acids, and three other compound classes, several of which have been associated with anticoccidial activity. Overall, the in vivo results suggest that LJF may exert potential anticoccidial effects against a field isolate of E. tenella. Phytochemical analysis provided preliminary compositional insights, and further studies are warranted to optimize extraction methods and evaluate efficacy at lower concentrations under additional in vitro and in vivo conditions. However, the current evidence remains insufficient to determine whether the field isolate exhibits reduced sensitivity to commercially available anticoccidial drugs, and additional studies are needed to clarify this issue.

Poultry doi: 10.3390/poultry5020027

Authors: Mircea Coroian Andrada Berbecaru Mihaly Fazakas Virginia Magdaș Cristian Magdaș Varga Erzsébet Fülöp Ibolya Adriana Györke

Backyard chicken farming is a longstanding practice in Romania, with over 13 million birds raised in such systems to provide households with essential sources of eggs and meat. Despite advantages such as low production costs and the potential for organic husbandry, backyard poultry remains highly vulnerable to parasitic infections due to limited biosecurity measures and minimal regulatory oversight. This study aimed to evaluate the efficacy of a plant-based anthelmintic product in naturally infected backyard flocks. Among the 35 backyard farms examined, 24 (68.6%) tested positive for helminth infections, with prevalence rates of 51.4% for Ascaridia galli/Heterakis gallinarum, 57.1% for Capillaria spp., and 40% for Strongyloides avium. Positive households were assigned to three groups: untreated control, fenbendazole-treated, and herbal product-treated. The plant-based formulation consisted of alcoholic extracts from seven locally sourced plants, Thymus serpyllum, Calendula officinalis, Inula helenium, Tanacetum vulgare, Origanum vulgare, Artemisia annua, and Artemisia absinthium, and was administered via drinking water at a dose of 5 mL/L for seven consecutive days. Anthelmintic efficacy was assessed using the fecal egg count reduction test (FECRT). Fecal samples were collected before treatment and on days 7, 14, and 21 post-treatment, and examined using flotation and the McMaster technique. Both the plant-based and fenbendazole-treated groups exhibited significant reductions in egg counts for A. galli/H. gallinarum (p ≤ 0.00001), although neither treatment reached the 90% efficacy threshold required for reliable parasitic control in poultry. The herbal formulation achieved a 91.33% reduction in fecal egg counts overall and a complete (100%) efficacy against Strongyloides avium at 7 and 21 days post-treatment, respectively. At 14 days post-treatment, the mean FECRT values across all parasite species ranged from 13.64% in the untreated control group to 71.86% in the fenbendazole-treated group and 67.11% in the herbal-treated group. The highest reduction was observed in the fenbendazole group against Ascaridia galli/Heterakis gallinarum (85.22 ± 11.86), while the lowest was recorded in the control group against S. avium (–31.63 ± 96.64). Overall, our findings indicate that plant-based anthelmintics are a promising, environmentally friendly option for organic backyard poultry systems, offering a viable alternative to conventional chemical treatments.

Poultry doi: 10.3390/poultry5020026

Authors: Filip Benko Tomáš Slanina Michal Ďuračka Miroslava Kačániová Eva Tvrdá

Efficient liquid storage of turkey semen is critical for artificial insemination, but its use is limited by bacteriospermia and oxidative damage. This study evaluated the effects of gentamicin supplementation in Glutac and Sperm Motility Medium (SMM) on bacterial load and sperm quality after 2 and 24 h of liquid storage. Semen from turkeys (n = 40) was assessed for motility, viability, plasma membrane and acrosome integrity, mitochondrial and metabolic activity, oxidative profile, apoptosis, DNA integrity, and microbiological status. The sperm motility and kinematic parameters declined significantly after 24 h in all the groups. However, both extenders (particularly SMM) maintained significantly higher motility than the untreated control. Gentamicin further improved the motility, viability, and plasma membrane and acrosome integrity. The mitochondrial activity and mitochondrial membrane potential were significantly higher in the extender-treated groups than in the controls at 2 and 24 h, whereas the superoxide and total ROS production were significantly higher in the controls. The total antioxidant capacity declined markedly in the untreated controls, especially after 24 h. Gentamicin significantly reduced bacterial load, most effectively in SMM, and decreased DNA fragmentation compared with the untreated controls. In conclusion, gentamicin supplementation—particularly in SMM—reduces bacteriospermia and oxidative stress while preserving turkey sperm quality during liquid storage.

Poultry doi: 10.3390/poultry5020025

Authors: Beatrice Grafl Peter Mitsch Ernst Wiesinger Josef Ziegerhofer Ivana Bilic Claudia Hess Dieter Liebhart Michael Hess

In recent years, outbreaks of inclusion body hepatitis (IBH) have been reported with increasing frequency worldwide. In Austria, the presence of fowl aviadenoviruses (FAdVs) and/or IBH has been documented sporadically. The present report describes a surge of natural IBH cases in fifteen Ross 308 broiler flocks. The clinical picture was characterized by the sudden onset of increased mortality in birds 3 to 15 days of age, persisting for approximately one week, resulting in cumulative flock mortality ranging from 2% to 27%. The main pathological findings were hepatitis with diffuse necrotic foci and petechial hemorrhages with intranuclear inclusion bodies by histology. FAdV was detected in liver samples from all affected flocks. Based upon partial hexon sequence analysis, FAdV serotype-11, species-D (FAdV-11, FAdV-D) was identified, showing complete sequence identity among broiler-derived strains and high identity with previous isolates from Austria and globally IBH-associated isolates. Furthermore, FAdV-11 DNA was detected in dead-in-shell embryos collected during the ongoing outbreak, originating from one suspect broiler breeder flock, confirming vertical transmission. Serological investigations of the suspect breeders confirmed the FAdV-11 infections within the studied timeframe. In conclusion, investigations confirmed vertical transmission of FAdV-11 and subsequent manifestation of IBH in broilers under field conditions, highlighting the epidemiological importance of broiler breeders in IBH outbreaks.

Poultry doi: 10.3390/poultry5020024

Authors: Johannes Niermeyer Johannes Demann Finn Petersen Georg Dusel Reindert Devlamynck Andreas Ulbrich Hans-Werner Olfs Heiner Westendarp

Global population growth is expected to increase poultry meat demand, intensifying the need for sustainable protein sources. Soybean meal, the primary protein feed for poultry, has negative associations with deforestation and long transport distances. Duckweed has emerged as a possible, more sustainable alternative due to its high growth rate and protein yield. The nutrient digestibility and performance effects of the duckweed species Lemna minor (L. minor) in broiler diets were investigated in two experiments. Experiment 1 determined the ileal digestibility of crude protein, amino acids, phosphorus, and metabolizable energy in L. minor. The digestibility of most amino acids in L. minor ranged from 70% to 96%, with lysine and methionine at 87% and 86%, respectively. At 48%, the digestibility of cysteine was markedly lower than that of the other amino acids. However, the digestibility of P exceeded 90%. The energy values of dry matter were 7.05 MJ AME and 6.13 MJ. Experiment 2 tested the inclusion of L. minor (up to 10%) in isoenergetic and isonitrogenous diets. No significant effects on nutrient digestibility, weight gain, feed intake, or feed conversion ratio were observed. Both experiments demonstrate that L. minor cultivated under controlled conditions is a highly digestible, reliable feed source. Its inclusion in broiler diets is feasible, as it does not impair performance, yet provides amino acid balance whilst ensuring biomass quality. These findings support L. minor as a novel protein alternative and warrant further research on higher inclusion rates.

Poultry doi: 10.3390/poultry5020023

Authors: Jitka Edrová Adriana Hofmanová Lukáš Zita Monika Okrouhlá Darina Chodová Lucie Kruntová Ondřej Krunt

Sexual dimorphism is a well-recognized factor influencing growth performance and meat quality in poultry; however, its effects remain less explored in Muscovy ducks. This study investigated the effect of sex on carcass traits, meat quality parameters, muscle fiber characteristics, and lipid composition in 14-week-old Muscovy ducks. Carcass dissection, physical and chemical meat analyses, and histological evaluation of breast muscle were performed in males and females. Sex markedly affected carcass performance, with males exhibiting higher live, slaughter, semi-eviscerated, and eviscerated weights, whereas females showed greater abdominal fat deposition and higher drip and processing losses, indicating reduced water-holding capacity. In the breast muscle, females displayed lower ultimate pH, higher yellowness (b*), and lower shear force values, suggesting more tender meat. Chemical composition differed between sexes, with males showing higher moisture and protein contents and lower intramuscular fat, accompanied by sex-related differences in fatty acid composition. Muscle fiber morphology also varied significantly, as males exhibited larger fiber diameters and cross-sectional areas in the breast muscles. Overall, these findings demonstrate that sex is a critical determinant of carcass yield, technological meat properties, and nutritional quality in Muscovy ducks, highlighting its importance for targeted production and processing strategies.

Poultry doi: 10.3390/poultry5020022

Authors: Leilane Rocha Barros Dourado Melina da Conceição Macêdo da Silva Pedro de Carvalho Gaio Iara Silva Sousa Francisca Luana de Araújo Carvalho Danielle Machado Ribeiro Azevedo Dáphinne Cardoso Nagib do Nascimento Daniel Biagiotti Simara Marcia Marcado José Luiz Leonardo de Araújo Pimenta

Broiler production efficiency depends on the capacity of different strains to utilize nutrients and minimize environmental losses. This study aimed to quantify the excretion and digestibility of dry matter, nitrogen, and phosphorus in Cobb 500, Ross 308, and Hubbard Flex strains at different ages under Southwest Piauí conditions. A total of 300 broilers of both sexes were distributed in a 3 × 2 factorial design (3 strains × 2 sexes) with five replicates, totaling 30 experimental units. The six-week trial included adaptation periods, excreta collection, and feed intake control each week. Dry matter, nitrogen, and phosphorus were analyzed in diets and excreta to calculate intake, excretion, and retention coefficients (DMR, NR, PR). Interactions between sex and strain were observed after 25 days for some variables. Males excreted 10.21% more phosphorus than females, and strain effects were mainly observed for phosphorus excretion, with Hubbard exhibiting lower excretion in the 32–35-day phase, Cobb presenting the highest, and Ross demonstrating intermediate excretion. Variations between sexes were observed within strains across ages. These results demonstrate that nutrient utilization is influenced by both strain and sex, highlighting the need for tailored nutritional strategies to improve feed efficiency and reduce environmental impact in broiler production.

Poultry doi: 10.3390/poultry5020021

Authors: Francesca Di Federico Alessandro Dal Bosco Luigia Bosa Marta Vispi Lorenzo Nompleggio Elisa Angelucci Simona Huja Cesare Castellini Simona Mattioli

Over the years, poultry supply chains have prioritized highly productive genetic lines to meet consumer demand, often at the expense of meat quality, animal welfare, and animal health. Recently, however, industry trends have shifted toward a greater awareness of welfare, reduced farming intensity, and improved product quality. In response, the European Chicken Commitment (ECC) has advocated for the use of slower-growing genotypes, even within conventional production systems. This study aimed to evaluate the meat quality of two ECC-approved chicken genotypes with differing growth rates—slow-growing (SG: 30–40 g/day, Kabir) and medium-growing (MG: 40–50 g/day, Ranger Gold) in comparison with a fast-growing strain (FG: >65 g/day, Ross 308). A total of 300 chickens were assigned to two experimental conditions: a control group (C), with spontaneous activity, and a treatment group (M), subjected to induced moderate kinetic activity. The results demonstrated that genotype influenced the meat quality of chickens raised indoors more significantly than kinetic activity. Comparisons revealed that SG and MG chickens exhibited superior meat quality, particularly regarding protein content, oxidative status, and a more suitable fatty acid profile. Overall, our findings support the adoption of ECC-approved genotypes in indoor systems to simultaneously improve animal welfare and enhance the nutritional and technological quality of poultry meat.

Poultry doi: 10.3390/poultry5020020

Authors: Tetiana I. Fotina Hanna A. Fotina Alexey V. Fotin Anatoliy I. Fotin Igor A. Ionov Olga V. Anisimova Darren K. Griffin Michael N. Romanov

High-quality, well-balanced feeding strategies are essential for optimizing poultry growth performance and for ensuring the safety of poultry products. Here, we evaluated the effects of chelated vs. inorganic trace minerals on the growth, survival and carcass characteristics of Cobb 500 broiler chickens. A large-scale feeding trial involved four dietary treatments at 21–35 days of age, with Group 1 receiving a control diet with mineral supplements of zinc (Zn), copper (Cu) and manganese (Mn) in sulfate form, based on a standard formulation. A further three experimental diets contained chelated forms of Zn (Group 2), Cu (Group 3) and a mineral premix MINTREX® that provides Zn, Cu and Mn (Group 4). Broilers were raised to 42 days of age under commercial production conditions. Feeding chelated trace minerals resulted in significantly higher body weights during the rearing period, including a 10% increase in pre-slaughter weight compared to the controls (p < 0.01). Moreover, survival rates improved from 87% in the controls to 95–96% in the treatment groups (p < 0.001), and carcass evaluation revealed a 15–17% increase in eviscerated carcass weight in birds fed chelated supplements (p < 0.05). Greater yields of muscle, liver and skin with subcutaneous fat were observed, as was improved production of total edible carcass components. Among the treatments, MINTREX® provided the greatest enhancement effects in performance and slaughter traits. These findings demonstrate that dietary chelated minerals, whether single or combined, may have positive effects on the broiler carcass yield and support their inclusion in poultry production systems.

Poultry doi: 10.3390/poultry5020019

Authors: Lena Sonnenschein-Swanson Silvia Baur-Bernhardt Annemarie Käsbohrer Marcus Georg Doherr Diana Meemken Mary-Ann Sommer Birgit Ursula Stetina Petra Weiermayer

A two-cohort feasibility study was conducted to investigate the potential role of homeopathic therapy in reducing antimicrobial use in turkeys. The objective of the analysis presented here was to describe the complex characteristics of the study farms. For analysis of heterogeneity, data of 25 turkey farms (7 homeopathy (H); 18 conventional (C)) were analyzed. Farms in cohort H had significantly higher numbers of poultry farms nearby and included outdoor husbandry, while those in cohort C included neither organic nor biodynamic husbandry types. During raising, a combination of straw and wood shavings was more frequent, while during fattening, only one type of litter was predominant. Very few additional significant differences were identified at farm level, while at production batch level, several further differences existed. When comparing the study cohort characteristics with national statistics, both cohorts seemed to perform better than the national average. The incidence of antibiotic treatment days was lower in cohort H compared to cohort C (C 0.14, H 0.01, p < 0.001), while production period-related mortality (C 3.7%, H 3.7%) was comparable. Our detailed collection of data, previously unavailable, provides a relevant insight and will enable the analysis of multivariable aspects linked to antimicrobial usage in turkey production.

Poultry doi: 10.3390/poultry5020018

Authors: José Rafael Wanderley Benício Angélica Sulzbach Amália Luisa Winter Berté Charles Fernando dos Santos Cristina Jardim Cezar Mariano Daiane Heidrich Mônica Jachetti Maciel Liana Johann Guilherme Liberato da Silva

The poultry red mite Dermanyssus gallinae (PRM) is a hematophagous ectoparasite of major veterinary and public health concern, recognized as a potential vector of zoonotic pathogens. Despite recent advances in characterizing its microbiota, the temporal dynamics of the microbial community remain poorly understood. Here, we conducted a longitudinal metabarcoding survey of engorged PRM collected from a commercial cage-free laying hen farm over the laying hen’s productive cycle (30–105 weeks). High-throughput sequencing of the 16S rRNA V3–V4 region generated 412,078 sequences, identifying 186 bacterial species across all samples. Microbial richness peaked at 30 weeks (164 species), but sharply declined thereafter, with only 28, 55, and 43 species detected at 60, 90, and 105 weeks, respectively. Ordination (NMDS) and PERMANOVA analyses revealed significant temporal restructuring of microbial communities (R2 = 0.76, p < 0.01), with distinct clustering across sampling points. A small subset of taxa persisted throughout time, including the genera Bartonella and Rickettsiella, while many species exhibited transient or stage-specific occurrence. Notably, zoonotic pathogens such as Staphylococcus aureus, Kocuria massiliensis, and Bartonella vinsonii were detected, suggesting that PRM may harbor microorganisms of potential medical and veterinary relevance. Overall, our findings demonstrate that PRM harbors a highly diverse but temporally dynamic microbiota, which progressively contracts into a community dominated by stable symbionts. These results highlight critical windows for microbial succession and reinforce the relevance of microbiome-based surveillance and integrated control strategies within a One Health framework.

Poultry doi: 10.3390/poultry5020017

Authors: Pia Muenster Dmytro Radko Adam Goddard Robert Harrison Doris Mueller-Doblies

Zoonotic Salmonella strains are major pathogens causing foodborne illness, and poultry products are among the main sources of infection. Biosecurity on poultry farms is central to preventing the introduction of Salmonella; together with vaccination, it can reduce the risk of meat and eggs becoming contaminated. Live Salmonella vaccines are conveniently administered via drinking water, and good vaccination practices are essential to ensure flock protection. This requires drinking water to be compatible with live vaccines. Data about the impact of water quality on vaccine viability are limited; therefore, this study investigated the impact of different water parameters on the stability of a bivalent live Salmonella vaccine. In addition, the impact of the most common disinfectants used for drinking water sanitization was assessed. Fluoride, nitrate, sulphate levels, and hardness had little impact on vaccine survival, while aluminium, arsenic, iron, and manganese levels had a pronounced, dose-dependent effect. pH value, conductivity, and chloride levels impacted the vaccine stability only at high levels. Free chlorine, chlorine dioxide, and hydrogen peroxide strongly reduced the viability of the vaccine, even though a water stabilizer offered protection from chlorine and chlorine dioxide but not from hydrogen peroxide. These findings highlight the importance of drinking water quality for effective vaccination.

Poultry doi: 10.3390/poultry5020016

Authors: Nicole Ahlig Barbara Tzschentke

The compatibility of economic efficiency and animal welfare is a major challenge given the increasing demand for animal-based foods. Various studies have shown that it is possible to promote the resistance and robustness of commercial poultry (primarily broilers) by modifying incubation temperatures. Focused on the histology of the Bursa fabricii, an important lymphatic organ in birds, the investigations in this paper aim to show whether short-term temperature changes during final incubation (+1 °C, 2 h/incubation day 17–20) could have an influence on the robustness of broilers compared to conventionally incubated ones. Overall, however, the temperature stimulation during final embryonic development did not result in any statistically significant morphological changes in the bursa or in the heterophil-to-lymphocyte ratio (HLR) that would clearly indicate improved immune function. However, there are obvious sex-specific differences. For instance, a sexual dimorphism could be seen in the parameters of follicle number, follicle density and in the HLR when looking at the absolute numbers. Calculation of the effect size using Cohen’s d showed that there was an effect on the relative weight of the Bursa fabricii (d = −0.28, d ♂ = −0.25, d ♀ = −0.35) cell density (d ♀ = −0.32), follicle density (d ♀ = 0.37) and the HLR (d = 0.24, d ♂ = 0.43), so that further investigations should be encouraged.

Poultry doi: 10.3390/poultry5010015

Authors: Sadao Kojima

Egg yolk coloration influences consumer perceptions of table eggs. Red pepper (Capsicum annuum) is a known dietary source of carotenoids, which enhances yolk pigmentation, but its effects in silky fowl (SF) remain unexplored. We examined how dried red pepper flakes influence blood biochemical parameters and egg quality in SF hens. Sixty hens were divided into three groups: basal ration (control), low supplementation (3.5 mg/100 g), and high supplementation (7.0 mg/100 g). During a 35-day feeding period, eggs collected in the final week were maintained at 4 or 25 °C for quality evaluations. Haugh units and the yolk index were decreased significantly in eggs maintained at 25 °C compared with those in the day 0 and 4 °C samples, whereas the yolk carotenoid content decreased with the storage duration, particularly in the high-supplementation group. CIELAB parameters (L*, a*, a/b), except for b*, were more strongly associated with the ZEN-NOH Yolk Color Chart Score than the DSM Yolk Color Fan Score, particularly in the high-supplementation group. In addition, serum high-density lipoprotein cholesterol was increased, and triglyceride levels were decreased in the high-supplementation group. In conclusion, dietary red pepper flakes enhance yolk pigmentation and lipid metabolism in SF hens. Moreover, ZEN-NOH YCCS provides a reliable indicator of the yolk color after dietary carotenoid supplementation.

Poultry doi: 10.3390/poultry5010014

Authors: Marcello Borges Estevão Weslane Justina da Silva Stéfane Alves Sampaio Júlia Marixara Sousa da Silva Ana Maria Vilas Boas Morais Nadielli Pereira Bonifácio Cíntia Minafra Cassia Cristina Fernandes Fabiana Ramos dos Santos Cibele Silva Minafra

This study evaluated the sanitization of fertile eggs using a blend of oregano (Origanum vulgare) and cinnamon (Cinnamomum verum) essential oils as an alternative to paraformaldehyde. The experiment was conducted at the Animal Biochemistry and Metabolism Laboratory of IF Goiano, Rio Verde Campus, using 344 incubatable eggs from ROSS breeder hens. A completely randomized design with four treatments and 86 eggs per tray was applied: no sanitization (control); conventional paraformaldehyde fumigation; sanitization with essential oil blend by spraying (nebulization); and sanitization with the essential oil blend by immersion. Hatchability performance showed 133 chicks hatched in both essential oil treatments (immersion and nebulization), like paraformaldehyde (134 chicks). There was a statistical difference for (p < 0.05) and chick weight at hatch was lower for eggs sanitized by immersion (38.54 g) compared to the control (44.50 g), paraformaldehyde (44.48 g), and nebulization (43.78 g). Fertility rates were 77.51%, 78.29%, 77.32%, and 73.67% for the control, paraformaldehyde, nebulization, and immersion treatments, respectively. Hatchability reached 80.67% for paraformaldehyde and 79.83% for nebulization. Fungal contamination was lowest with paraformaldehyde (9 occurrences), followed by immersion (12), while the control and nebulization showed similar counts (19). Overall, sanitization of fertile eggs with the cinnamon–oregano essential oil blend applied by nebulization demonstrated performance comparable to paraformaldehyde, indicating its potential as a natural sanitizing alternative.

Poultry doi: 10.3390/poultry5010013

Authors: Miao Yu Xiumei Li Xin Zhao Jinghai Feng Minhong Zhang

Heat stress poses a considerable challenge to the modern poultry industry by negatively impacting immune system maturation and eliciting inflammatory responses. Peroxisome proliferators-activated receptors α (PPARα), predominantly expressed in metabolically active tissues such as skeletal muscle, are essential for regulating the inflammatory process. Moreover, our recent research has found that heat stress down-regulates the transcription of PPARα in broiler chickens. To study if PPARα regulation is involved in heat-stress-induced skeletal muscle inflammatory response in broiler chickens, 180 male Arbor Acres (AA) broilers aged 22 days were randomly assigned to three experimental groups: a thermoneutral condition group at 21 °C, a heat stress group at 31 °C and a heat stress group at 31 °C supplemented with the PPARα activator fenofibrate. After 7 days of adaptive feeding, the broilers were subjected to a 14-day formal experimental phase. Results demonstrated that heat stress decreased the spleen and thymus index and increased serum and breast muscle inflammatory factor concentrations (p < 0.05). Moreover, heat-stress-induced abnormal breast muscle fiber morphology in broiler chickens. Furthermore, heat stress significantly up-regulated nuclear factor kappa-B (NF-κB) expression in boiler chickens (p < 0.05). However, activating PPARα through fenofibrate improved the growth performance (p < 0.05), enhanced immune organ indexes (p < 0.05), reduced inflammatory factor concentrations (p < 0.05), alleviated breast muscle fiber morphology damage and suppressed NF-κB expression (p < 0.05) in the breast muscle of broiler chickens. Based on our previous research, these results collectively underscore that heat stress induced inflammation and up-regulated NF-κB in the breast muscle of broiler chickens by inhibiting PPARα.

Poultry doi: 10.3390/poultry5010012

Authors: Pamella Pryscila de Alvarenga Bissoli Maciel de Lima José Andrew de Lira Barbosa Giulia Cancian Vieira Júlia de Castro Campos Pereira Mateus Tinelli Menegalle Huarrisson Azevedo Santos Robson Mateus Freitas Silveira Felipe Dilelis

This study aimed to evaluate the performance, nutrient digestibility, intestinal health, and duodenum gene expression of broilers challenged with Eimeria spp. supplemented with or without monensin sodium. A total of 144 male chicks were used, distributed in a completely randomized design with three treatments: unchallenged control (UN), challenged control (CC), and CC + 100 mg/kg of monensin sodium (MON). Six replicates of eight birds each were used. At 14 days of age, the challenged groups were inoculated with a mixture of Eimeria oocysts, 12,500 E. maxima, 62,500 E. acervulina, and 12,500 E. tenella oocysts/chick. Coccidial challenge impaired growth performance and nutrient digestibility and induced intestinal damage, as evidenced by reduced body weight gain and feed intake (p < 0.001), lower apparent digestibility coefficients (p < 0.001), and altered intestinal morphometry and ISI score in the jejunum and cecum (p < 0.001). Monensin supplementation partially alleviated these negative effects, improving performance and nutrient digestibility (p < 0.001) and delaying oocyst excretion (p = 0.006) when compared with the CC group. However, the duodenal expression of tight junction-related genes, as well as intestinal integrity and health parameters, remained impaired despite monensin supplementation. It is concluded that monensin preserves nutrient digestibility and attenuates performance loss in broilers challenged with Eimeria spp. but not reduced intestinal damage.

Poultry doi: 10.3390/poultry5010011

Authors: Karen Schemmann Denise K. Geßner Erika Most Klaus Eder

In most countries, male siblings of laying hybrids are culled immediately after hatching because their rearing is economically unfeasible due to low growth performance, poor feed efficiency, and a body composition unacceptable to consumers. In Germany, however, culling male day-old chicks has been prohibited for animal welfare reasons since 2022, making their rearing mandatory. Currently, no recommendations exist for protein and amino acid supply for these birds. This study aimed to determine the requirements for standardized ileal digestible (SID) methionine + cysteine (Met + Cys) and SID lysine (Lys) during the starter period (days 1–21) in male LSL Classic chicks by a dose–response approach. Two trials were conducted with 120 male chicks each, fed six diets containing SID Met + Cys concentrations ranging from 0.36% to 0.71% (Trial 1) or SID Lys concentrations ranging from 0.50% to 0.89% (Trial 2). Optimal concentrations were estimated using broken-line and exponential models based on body weight gain, feed intake, and feed conversion ratio. Considering all criteria, the optimal SID Met + Cys concentration was 0.58% (0.42 g/MJ AMEN), and the optimal SID Lys concentration was 0.74% (0.56 g/MJ AMEN). The calculated optimum SID Met + Cys:SID Lys ratio when standardized to an identical energy level was 74:100. These findings provide a basis for adjusting SID Met + Cys and SID Lys levels in starter diets for male chicks of a layer breed, supporting more efficient and sustainable rearing practices under current animal welfare regulations.

Poultry doi: 10.3390/poultry5010010

Authors: Jakub Vorel Ondřej Krunt Darina Chodová Lucie Kruntová Adriana Hofmanová Lukáš Zita

This study evaluated the effect of rearing conditions with outdoor access on carcass traits, technological meat quality, and muscle fibre morphology in broiler chickens. Hubbard JA757 broilers were reared until 81 days of age under either control or experimental conditions. Both groups were housed indoors under identical management until day 35; thereafter, the experimental group had access to an outdoor paddock, while the control group remained indoors. At 81 days of age, birds were slaughtered, carcass composition was recorded, and breast (pectoralis major) and thigh (biceps femoris) muscles were analyzed for pH, colour, cooking loss, and shear force. Muscle fibre characteristics were assessed histochemically. Control birds showed higher slaughter and chilled carcass weights, whereas experimentally reared birds exhibited higher carcass yield, lower breast proportion, higher thigh proportion, and reduced abdominal fat. Experimental rearing was associated with higher L* values, higher shear force, and lower cooking loss in both muscles. In the pectoralis major, fibre density was higher in controls, while fibre diameter was higher in the experimental group. In the biceps femoris, the experimental group showed a higher proportion of oxidative βR fibres and larger fibre cross-sectional areas. These results demonstrate that the rearing system influences carcass composition, technological meat properties, and muscle fibre characteristics, leading to distinct phenotypic and technological differences between the groups.

Poultry doi: 10.3390/poultry5010009

Authors: Jelena Nedeljković Trailović Branko Petrujkić Saša Trailović Dragoljub Jovanović Milutin Đorđević Darko Stefanović Nataša Tolimir Darko Marinković Stamen Radulović

The experimental study was performed to determine the efficacy of a mycotoxin detoxification agent (MS) at a concentration of 0.2% in reducing the toxicity of aflatoxin B1 (AFB1) and ochratoxin A (OTA), alone or in combination, and to examine its effect on performance, pathohistological (PH) changes, and residues of these toxins in the tissues of broiler chicks. A total of 88 broilers were divided into eight equal groups: group C, the control group (fed a commercial diet without any additives); group MS, which received the mycotoxin detoxification agent (MS) (supplemented with 0.2%); group E I (0.2 mg AFB1/kg of diet); group E II (0.2 mg AFB1/kg of diet + MS 0.2%); group E III (1.5 mg OTA/kg of diet); group E IV (1.5 mg OTA/kg of diet + 0.2% MS); group E V (combination of 0.2 mg AFB1/kg, 1.5 mg OTA/kg of diet); and group E VI (combination of 0.2 mg AFB1/kg, 1.5 mg OTA toxin + 0.2% MS). Results show that feed containing AFB1 and OTA, individually or in combination, negatively affects health, production results, and PH changes in tissues, as well as the presence of mycotoxin residues in the liver and breast muscles of poultry. The addition of a new multicomponent preparation for the detoxification of MS mycotoxins in feed with AFB1 and OTA individually and in combination had a positive effect on TM (BW), growth (BWG), consumption and FCR conversion coefficient, and microscopic lesions in organs. The concentration of OTA residues in the liver and chest muscles was significantly lower in chickens fed a diet with the addition of 0.2% MS of the mycotoxin detoxification preparation.

Poultry doi: 10.3390/poultry5010008

Authors: Edney Pereira da Silva Michele Bernardino de Lima Rita Brito Vieira Nilva Kazue Sakomura

The maximum protein or nitrogen deposition is commonly used as the basis for modeling the amino acid intake in growing birds. In previous studies, the exponential functions of the nitrogen balance data were used to estimate the theoretical maximum for nitrogen deposition (NDmaxT) as a reference model for the amino acid intake. However, this amino acid intake value is only valid for the period in which the NDmaxT was estimated. Additionally, physiological changes, such as the rapid development of reproductive organs and associated increases in protein deposition that occur in the period before the first egg is laid, should be considered in the models. Thus, this study was conducted to model the daily NDmaxT of pullets and integrate this value into the factorial model to estimate the daily methionine + cysteine (Met+Cys) intake. Our results showed that, up to 63 days of age, the values of NDmaxT obtained via the modeling procedure were 11% higher than the values predicted using the Gompertz function. At 105 days, there was a protein deposition peak from the growth of the reproductive organs, which contributed 14% of the variation in the model in this age. Alongside these factors, the integration of the models enabled daily Met+Cys estimates consistent with the literature; however, the recommendations varied according to the targeted daily protein deposition (50% or 60% of NDmaxT), daily feed intake, and amino acid utilization efficiency. The modeling approach demonstrated here for Met+Cys can be used to model other amino acid requirements and can be extended to other species.

Poultry doi: 10.3390/poultry5010007

Authors: Leya Susan Viju Divya Joseph Poonam Gopika Vinayamohan Kumar Venkitanarayanan

Campylobacter jejuni (CJ) is a major foodborne pathogen with chickens serving as the reservoir host. This study investigated the efficacy of linalool, a Generally Recognized as Safe (GRAS) phytochemical, as an in-feed intervention to reduce CJ colonization in broiler chickens. Three independent trials were conducted using 212-day-old Cornish Cross chicks per trial. Of these, 192 birds were randomly allocated to eight treatment groups (n = 24/group): negative control, linalool-only controls (1.0%, 1.5%, and 1.8%), positive control (CJ only), and CJ-challenged birds supplemented with linalool at 1.0%, 1.5%, or 1.8%. Linalool supplementation commenced on day 0, and birds were orally challenged with approximately 9 log10 CFU of CJ on day 7. Cecal CJ populations were enumerated on days 14, 24, and 34. Positive control birds harbored approximately 6–7 log CFU/g of CJ in the ceca, whereas linalool supplementation significantly reduced CJ colonization (p < 0.05) by 2–3 log on day 14 and by 3–5 log on days 24 and 34. No adverse effects of linalool were observed on body weight, feed intake, or feed conversion ratio. Additionally, RT-qPCR analysis demonstrated downregulation (p < 0.0001) of key CJ virulence and colonization-associated genes. These findings suggest that dietary linalool is a potential strategy to reduce CJ colonization in broiler chickens; however, large-scale studies under field conditions are warranted.

Poultry doi: 10.3390/poultry5010006

Authors: Muhammed Shafeekh Muyyarikkandy Praveen Kosuri Mary Anne Amalaradjou

With growing emphasis on antibiotic-free poultry production, functional probiotics represent a promising strategy to improve gut health and reduce pathogen transmission. This study characterized three lactic acid bacteria (LAB) strains Lactobacillus delbrueckii subsp. bulgaricus NRRL-B-548 (LD), Lacticaseibacillus paracasei DUP-13076 (LP), and Lacticaseibacillus rhamnosus NRRL-B-442 (LR) for their probiotic potential and evaluated their efficacy against Salmonella enterica in poultry. The LAB strains were assessed for acid and bile tolerance, lysozyme resistance, cholesterol assimilation, antimicrobial activity, surface hydrophobicity, epithelial adherence, hemolysis, and antibiotic susceptibility. Genomic analysis was performed to identify genes associated with probiotic functionality. The protective potential of LR and LP was further validated in hatchlings using a hatchery spray model challenged with Salmonella Enteritidis. All strains survived simulated gastric and intestinal conditions, exhibited strong adhesion to epithelial cells, and demonstrated high hydrophobicity, indicating robust colonization capacity. The LAB significantly inhibited Salmonella Enteritidis, S. Typhimurium, and S. Heidelberg growth in vitro and remained sensitive to clinically relevant antibiotics. In vivo application of LR and LP to hatching eggs markedly reduced S. Enteritidis colonization in the liver, spleen, and ceca of hatchlings. Further, genomic profiling of the LAB strains revealed genes for bacteriocin production, exopolysaccharide synthesis, and carbohydrate metabolism supporting probiotic function. In summary, the evaluated LAB strains exhibit multiple probiotic attributes and strong anti-Salmonella activity, confirming their potential as safe, hatchery-applied probiotics for improving gut health and biosecurity in poultry production systems.

Poultry doi: 10.3390/poultry5010005

Authors: Frank W. Edens

Heat shock protein (HSP) gene families are known to be expressed preferentially over normal cellular proteins when poultry cells are exposed to environmental stressors. Bordetella avium infection leads to bordetellosis, which is characterized by severe inflammation of the tracheal epithelium, representing a severe stressor for the infected turkey poult. The purpose of this experiment was to examine the expression of HSP60 and HSP70 in the tracheae of B. avium-challenged poults. Tracheae were dissected from five poults per treatment at 7, 11, 14, and 21 days of age, and snap-frozen rings were examined immunohistochemically for the presence of HSP60 and HSP70 using HSP60 and HSP70 monoclonal antibodies (MABs). Infected poults expressed HSP60 predominantly on the apical surface of ciliated epithelial cells and weakly near the nucleus, and HSP70 was expressed only in the cytoplasm. Early in the development of bordetellosis, infected poults expressed more HSP60 and HSP70 than control poults of the same age, but at 14 days after infection, infected birds showed significantly decreased HSP60 proteins, which was associated with loss of tracheal epithelium. With loss of tracheal epithelium, the expression of HSP70 decreased at 11 days in the infected poults, and by day 21, very low levels of the proteins were observed in the infected poults compared to control poults with intact tracheal epithelium. It was concluded that decreased expression of HSP60 was indicative of HSP60 proteins becoming antigenic targets for the host’s immune system since immunologically targeted B. avium cells express GroEL (highly conserved HSP60 family equivalent) and DnaK (highly conserved HSP70 equivalent). The potential targeting of host and pathogen HSP60 by the innate immune system could feasibly facilitate loss of tracheal epithelium during the development of bordetellosis.

Poultry doi: 10.3390/poultry5010004

Authors: Muhammad Naeem Arjmand Fatima Rabin Raut Rishav Kumar Zahidul Tushar Farazi Rahman Dianna Bourassa

This review explores strategies to enhance meat quality in poultry, focusing on both management and genetic methods. Poultry meat quality is influenced by many factors, including rearing conditions, nutrition, animal welfare, and post-slaughter processing. Key management factors such as stocking density, ventilation, temperature, and humidity are emphasized for their significant impact on bird welfare and the resulting meat texture, color, and microbial stability. Welfare-enhancing practices like gentle handling, environmental enrichment, and thermal comfort are highlighted for their direct effects on stress levels and meat properties such as water-holding capacity and pH. Innovations in slaughtering and chilling techniques, including electrical and gas stunning and rapid chilling, are shown to preserve meat quality and prevent common defects like pale, soft, and exudative (PSE) or dark, firm, and dry (DFD) meat. The review also underscores the importance of hygiene protocols, hazard analysis and critical control points (HACCP) systems, and traceability technologies to ensure food safety and foster consumer trust. On the genetic front, it discusses conventional selection, marker-assisted selection (MAS), and genomic selection (GS) as tools for breeding birds with better meat quality traits, including tenderness, intramuscular fat, and resistance to conditions like woody breast. Functional genomics and gene editing are identified as the leading edge of future advances. Ultimately, the review advocates for an integrated approach that balances productivity, quality, animal welfare, and sustainability. As consumer expectations increase, the poultry industry must adopt precise, science-based strategies across the entire production process to reliably deliver high-quality meat products.

Poultry doi: 10.3390/poultry5010003

Authors: Tilemachos Mantzios Konstantinos Kiskinis Theoni Renieri Georgios A. Papadopoulos Ilias Giannenas Dimitrios Galamatis Panagiotis Sakkas Paschalis Fortomaris Vasilios Tsiouris

Numerous commercial products are used in poultry farms to maintain water quality and prevent pathogen dispersion, but their actual impact on broiler chicks’ performance and gut health remains underreported. This study aimed to investigate the effects of three commercial poultry water disinfectants on broiler chicks’ performance and the physicochemical characteristics of gastrointestinal content when continuously added to drinking water. A total of 144 one-day-old Ross® 308 broiler chicks were randomly allocated into four treatment groups: Group A (negative control), Group B (0.01–0.025% v/v Product A [H2O2 + silver complex]), Group C (0.01–0.04% v/v Product B [H2O2 + peracetic acid]), and Group D (0.05–0.1% w/v Product C [peroxides]). Body weight (BW) was measured weekly, while average daily weight gain (ADWG), average daily feed intake (ADFI), and feed conversion ratio (FCR) were calculated for different time periods. Additionally, on days 15 and 40, the pH of the crop, gizzard, duodenum, jejunum, and cecum contents was assessed, while the viscosity of jejunal and ileal contents were also measured. Statistical analysis revealed that all water disinfectants significantly (p ≤ 0.05) reduced BW, ADWG, and ADFI during the early growth phase, followed by either recovery or stabilization in the later stages. Drinking water disinfectants induced significant changes in intestinal physicochemical parameters, including reductions in pH of the content in the jejunum (p ≤ 0.05) during early growth and increased gizzard pH (p ≤ 0.05) and digesta viscosity (p ≤ 0.05) at later ages. These findings suggest that continuous water disinfection can suppress broiler chicks’ performance during the early stages of growth while significantly altering the physicochemical characteristics of gastrointestinal content. Further research is needed to investigate the mechanism that underlaying these results and optimize dosage schemes that balance pathogen control with the health, welfare, and performance of broilers.

Poultry doi: 10.3390/poultry5010002

Authors: Francisco Antonio Cigarroa Vázquez Jaime Bautista Ortega Víctor Hugo González Torres Said Cadena Villegas Roberto de la Rosa Santamaría Dany Alejandro Dzib Cauich Rodrigo Portillo Salgado

Male turkeys are raised mainly for meat production due to their high carcass yields and good capacity to convert food into meat. However, their carcass characteristics remain poorly understood. The objective of the study was to describe the carcass traits of 45 male native Mexican turkeys raised in the municipality of Champoton, Mexico, using principal component analysis (PCA). Fourteen carcass traits, namely, slaughter weight (SW), hot carcass weight (HCW), cold carcass weight (CCW), dressing percentage (DP), neck weight (NEW), foot weight (FEW), breast weight (BRW), thigh weight (THW), drumstick weight (DRW), wing weight (WIW), back weight (BAW), gizzard weight (GIW), heart weight (HEW), and liver weight (LIW), were collected. Pearson’s correlation analysis revealed strong positive relationships among carcass variables, with the highest correlations observed between CCW and HCW (r = 0.99; p < 0.001), SW and HCW (r = 0.98; p < 0.001), and SW and CCW (r = 0.98; p < 0.001). Hierarchical clustering identified four main groups of variables with similar correlation patterns. Three principal components (PCs) with eigenvalues greater than 1.0 were extracted, explaining 85.48% of the total variance in carcass traits. The first principal component (PC1) contributed 72.81% of the total variation (eigenvalue = 10.19), with high loadings (>0.70) for CCW (0.98), HCW (0.98), SW (0.98), DRW (0.95), BRW (0.91), WIW (0.90), THW (0.89), HEW (0.87), BAW (0.81), and FEW (0.82), representing a general size factor. PC2 explained 6.86% of the variance (eigenvalue = 0.96), characterized by a negative loading for DP (−0.64) and positive loadings for GIW (0.35) and LIW (0.34). PC3 accounted for 5.81% of the variance (eigenvalue = 0.81), with a negative loading for LIW (−0.63) and positive loadings for NEW (0.51) and FEW (0.46). Communality values exceeded 0.85 for all variables, indicating adequate representation in the reduced dimensional space. It was concluded that PCA effectively reduced dimensionality while retaining 85.48% of original information and can be used for the improvement of the carcass traits of male native Mexican turkey breeding programs.

Poultry doi: 10.3390/poultry5010001

Authors: Taylor K. O’Lear Reid Mark S. Edwards Tryg J. Lundquist Zachary D. McFarlane Siroj Pokharel Ruth E. Spierling Mohammed Abo-Ismail Darin C. Bennett

The egg industry continues to search for alternative feed ingredients that support production efficiency, enhance egg quality, and add nutritional value. Microalgae are rich in protein, pigments, and long-chain polyunsaturated fatty acids, making them promising candidates for poultry diets. This study evaluated the effects of dietary inclusion (1 and 2%) of four microalgae species, Arthrospira platensis (Spirulina), Hydrodictyon sp., Uronema sp., and Vaucheria sp., on laying hen performance, egg quality, yolk fatty acid composition, and bone strength. Seventy-six Lohmann LSL-Lite hens (92 weeks of age) were randomly assigned to nine treatments (control diet or one of eight microalgae diets). Feed intake, egg production, egg mass, feed conversion ratio, eggshell traits, yolk color, yolk fatty acids, and tibial breaking strength were measured. Inclusion of microalgae did not negatively affect hen performance, egg quality, nor bone strength. Spirulina significantly improved egg production and egg mass (p < 0.05). Increasing levels of Spirulina, Hydrodictyon sp., and Uronema sp. enhanced yolk color (all p < 0.05), while Vaucheria sp. showed no effect (p > 0.05). Yolk fatty acid profiles were only modestly altered, with increased docosahexaenoic acid observed in hens fed Hydrodictyon and Uronema (p < 0.05). In conclusion, low-level dietary inclusion of these microalgae species appears safe for laying hens and may provide added value through improved yolk pigmentation and modest omega-3 enrichment.

Poultry doi: 10.3390/poultry4040061

Authors: Sabuj Kanti Nath Md. Sahidul Islam Md Taslim Hossain Md. Monirul Islam Rahima Akther Dipa Tithe Saha Md. Shahadat Hossain Subir Sarker Saranika Talukder

This study evaluated the effects of matrix-dosed protease supplementation on growth performance, nutrient utilization, intestinal morphology, serum biochemistry, carcass traits, and economic return in broiler chickens. A total of 240 Cobb 500 chicks were assigned to six dietary treatments (T0–T5) with four replicates of 10 birds each for 33 days. Protease supplementation, particularly with protease F at 250 g/tonne (T5), significantly increased body weight at day 7 (163.0 ± 1.4 g; p = 0.002) and day 21 (854.0 ± 7.0 g; p = 0.014), and improved the feed conversion ratio at day 33 (1.54 ± 0.01; p = 0.002). Birds in the T5 group consistently exhibited the highest serum total protein (p < 0.001 on Day 21; p = 0.002 on Day 33), albumin (p < 0.001 on both days), and creatinine (p < 0.001 on Day 21; p = 0.006 on Day 33), along with reduced low-density lipoprotein (LDL) levels (p < 0.001 on Day 21; p = 0.002 on Day 33). Intestinal morphology was also enhanced, with villus height increasing to 874.0 ± 1.0 µm at day 21 and 931.0 ± 1.0 µm at day 33, accompanied by greater villus height-to-crypt depth ratios (11.23 ± 0.02 and 12.59 ± 0.01, respectively; p < 0.001). Moreover, apparent ileal digestibility of dry matter, crude protein, metabolizable energy, and amino acids were improved in T5 compared with the control and other treatments. Economic analysis showed the highest profit and return on investment (7.01%) in T5, followed by T4 and T2. These findings indicate that matrix-based protease supplementation enhances growth, nutrient absorption, and gut morphology while delivering substantial economic benefits, making it a cost-effective strategy for improving broiler productivity and profitability in commercial production systems.

Poultry doi: 10.3390/poultry4040060

Authors: Leonardo Willian de Freitas Felipe Dilelis Noédson de Jesus Beltrão Machado Débora Vaccari Quaresma Christiane Silva Souza Ana Paula Silva Ton Cristina Amorim Ribeiro de Lima

Three experiments were conducted to evaluate methodologies and determine the digestibility of calcium (Ca) in ingredients of animal origin, using a completely randomized design. In the first experiment, the direct, regression, and substitution methods were compared to determine the true digestibility of calcium in fishmeal (FM). The true ileal digestibility coefficients (TIDCs) obtained were 0.7558 (substitution), 0.6856 (direct), and 0.6130 (regression). Compared with the regression method, the substitution method resulted in greater digestibility. In the second experiment, the TIDCs of three meat and bone meals (MBM) were evaluated by the direct method. The observed values were 0.6212 (MBM1), 0.5393 (MBM2), and 0.8181 (MBM3). The MBM3 resulted in greater digestibility, while there was no significant difference between MBM1 and MBM2. In the third experiment, the TIDC values of the calcium in three poultry byproduct meal (PBM) samples were determined by the direct method, with coefficients of 0.9440 (PBM1), 0.8673 (PBM2), and 0.9127 (PBM3). No significant differences were observed between the evaluated PBM. The substitution and direct methods were effective for FM. The TIDCs of the MBMs ranged from 0.5393 to 0.8181, whereas those of the offal meals ranged from 0.8673 to 0.9440, indicating the importance of considering the differences in calcium digestibility among the ingredients. The direct method is the most efficient and recommended method for estimating true Ca digestibility because of its simplicity and reduced need for analysis and animals. Individually evaluating each source of Ca in broiler feed formulations is essential because of the wide variation in digestibility between them.

Poultry doi: 10.3390/poultry4040059

Authors: Valeriy G. Narushin Michael N. Romanov Darren K. Griffin Sabine Klein Attila Salamon Sara Copeland Cormac O’Shea John P. Kent

In bird eggs, the theoretical expectation of a primary sex ratio (at conception) of 50:50 males/females often fails to materialize. Using PCR technology for sex verification in this pilot study, we evaluated the primary sex ratio of 128 fertilized domestic goose eggs (Anser anser) early in the laying season. Over 24 consecutive days of egg collection, 37% more males were found (58% males vs. 42% females). This male-biased trend gradually declined over the period, but an excess of males was still observed. Among the factors for predicting the male sex ratio bias in a particular goose was the egg weight, i.e., heavier eggs tended towards a male phenotype. The embryo sex of the first egg laid and the egg weight change dynamics over the laying period were also noted. The correlation between actual and predicted data was calculated, taking into account three parameters, and found to be 0.724. To explain the effect of an implicit random/non-random process more adequately, we introduced the concept of biased randomness. As well as being of academic interest, research on sex ratio bias is crucial for goose breeding/reproduction programs and important as a step towards understanding the physiological mechanisms that underly sex ratio bias in these animals.

Poultry doi: 10.3390/poultry4040058

Authors: José Ignacio Salgado Pardo Antonio González Ariza Juan Vicente Delgado Bermejo Ignacio Castro Castillo Cecilio Barba Capote María Esperanza Camacho Vallejo

The present study provides a socio-economic characterization of an endangered turkey population in Europe for the first time, using the example of a southern Spanish population. To this end, 10 Andalusian turkey breeders were subjected to a 102-item survey, which included the following sections: personal and educational profile, the role of women in breeding, availability and conditions of facilities, welfare conditions, other equipment, maintenance and hygiene, farm access, feeding management, reproductive and replacement management, mortality, market value, and motivations for breeding. The results exhibited a wide variety in the breeder and rearing system attributes. However, the respondents agreed that rearing local breeds was a non-professionalized hobby. Farmers have generally old facilities and makeshift equipment for breeding the animals, which show strong ancestral instincts and a low requirement for breeding. The main purpose of their rearing is for self-consumption; however, there is an established sale demand for meat associated with Christmas. Breeders show a strong emotional motivation for the preservation of this ancestral population, which shares the rearing system with other endangered breeds. Three different profiles of breeders, traditional, neo-rural, and new-peasant, are responsible for maintaining the population selflessly and without administrative support.

Poultry doi: 10.3390/poultry4040057

Authors: Sara Kovačević Nevena Grković Branko Suvajdžić Milijana Sindjić Vladimir Dimitrijević Zsolt Becskei Nikola Čobanović

This study aimed to describe a new broiler meat quality class—red, soft, and exudative (RSE) meat—and to propose novel classification criteria. Two-step cluster analysis assigned 132 broilers into five meat quality classes using ultimate pH, drip loss, and L* values: pale, soft, and exudative (PSE); pale, firm, and nonexudative (PFN); RSE; red, firm, and nonexudative (RFN); and dark, firm, and dry (DFD) meat. PSE meat showed the lowest plasma superoxide dismutase activity, highest malondialdehyde activity, greater live and carcass weights, higher breast and leg yields, the lowest initial and ultimate pH, highest initial temperature, the lightest colour (the highest L* and b* values, and the lowest a* value), and the greatest drip, thawing, and cooking losses. RFN meat had the highest superoxide dismutase activity, lowest malondialdehyde activity, and remained within the optimal range for ultimate pH, drip loss, and L* value, generally occupying a midpoint between PSE and DFD meat. RSE meat shared the poor water-holding capacity of PSE but differed by showing a colour similar to RFN and an optimal ultimate pH. PFN meat had firmness comparable to RFN, with appropriate water-holding capacity and optimal ultimate pH, but an undesirably pale colour resembling PSE. DFD meat displayed the highest initial and ultimate pH, lowest drip, thawing, and cooking losses, darkest colour (the lowest L* value), and lowest protein content. This study provides the first evidence of RSE meat in broilers and proposes a classification system based on ultimate pH, drip loss, and L* values to distinguish five quality classes. Further studies are required to validate these findings and develop preventive strategies.

Poultry doi: 10.3390/poultry4040056

Authors: Edward Diehl Ellen van Eerden Masja Duijster René Kwakkel

Early growth in broilers depends on the rapid development of supply organs that enable nutrient use and support the growth of demand tissues such as muscle and bone. This study evaluated whether increasing dietary fat (and thereby AME) and amino acid concentration in starter diets enhances supply organ development and growth performance in Cobb male broilers. A 2 × 2 factorial design compared two fat levels, corresponding to two AME levels (F− 2750 vs. F+ 3050 kcal/kg), and two standardized ileal digestible lysine levels (AA− 1.0% vs. AA+ 1.2%) in an ideal ratio, to other essential AAs during days 0–11. Higher amino acid concentration consistently improved body weight gain, feed efficiency, and nutrient utilization throughout the trial, whereas the benefits of higher AME were mainly observed during the first 11 days. Diets high in both fat and amino acids reduced early feed intake, suggesting satiety effects. The effects on supply organ development were limited; only the pancreas and small intestine exhibited treatment-related differences in relative weight or allometric growth. In conclusion, increased amino acid concentration in starter diets improved overall broiler performance and nutrient efficiency, whereas dietary fat provided only short-term benefits. These improvements were not consistently associated with morphological changes in supply organs.

Poultry doi: 10.3390/poultry4040055

Authors: Geise Linzmeier Fernando de C. Tavernari Aline Zampar João V. Strapazzon Paulo V. Oliveira Roger Wagner Aleksandro S. da Silva Marcel M. Boiago

It is well established that both the age of the breeder hen and the type of incubator can influence the efficiency of the hatching process. However, there is a lack of information in the literature regarding the interaction between these two factors. This study evaluated the effects of incubator type (multi-stage vs. single-stage) and breeder hen age (35 and 61 weeks) on the hatching parameters, embryonic oxidative stress, performance, carcass yield, and meat quality of male broiler chickens. The embryo livers from the multi-stage incubator presented significantly higher NADP oxidase (NOX) values (p = 0.022), indicating elevated oxidative stress. A significant interaction between breeder age and incubator type was observed for the thiol concentrations, with embryos from older hens incubated in the multi-stage system showing higher thiol levels compared to those from the single-stage system. Birds from these older breeders demonstrated increased breast yield, feed intake, and weight gain, without significant changes in feed conversion ratio. Additionally, the single-stage incubator was associated with reduced embryonic oxidative stress, lower egg weight loss during incubation, and improved early performance of chicks during the first week post-hatch. In conclusion, beyond the previously recognized benefits of single-stage incubation systems, our findings highlight their potential to mitigate oxidative stress in embryos, thereby enhancing early chick development.

Poultry doi: 10.3390/poultry4040054

Authors: Gert Coertze Rene Kwakkel Laura Star Christine Jansen van Rensburg

Limited published data are available on the ratio of digestible non-essential amino acid (DNEAA) to digestible lysine (DLys) for layers. The effect of different DNEAA-to-DLys ratios on performance parameters of Hy-Line Silver-Brown layers was studied from 20 to 35 weeks. Experimental design was randomized with ten dietary treatments of increasing concentrations of DNEAA-to-DLys ratio (10.61, 10.84, 11.08, 11.31, 11.54, 11.77, 12.00, 12.23, 12.46, 12.69). Average daily feed intake, total feed intake, laying rate, cumulative egg number, egg weight, hen body weight, feed conversion ratio, egg mass output, albumen weight, eggshell weight, yolk weight, eggshell breaking strength, eggshell thickness, carcass and feather weight, carcass protein, carcass fat, liver weight, and liver fat were recorded. Changing the DNEAA/DLys ratio did not affect production parameters. Yolk and yolk-to-egg weight decreased with an increase in DNEAA/DLys ratio, while albumen-to-yolk and albumen-to-egg weight increased. The DNEAA/DLys ratio did not affect carcass or liver composition, but liver and liver-to-body weight (%) decreased as the DNEAA/DLys ratio increased. Hy-Line Silver-Brown layers during peak production sustained egg production and quality even on the lowest ratio in this study. Low DNEAA/DLys ratios increased liver fat deposition.

Poultry doi: 10.3390/poultry4040053

Authors: Carla Lourena Cardoso Macedo Lourenço Débora Fonteles Lima Angefferson Bento Evangelista Alfredo Pinto Rodrigues João Marcelo Lopes de Abreu Ednardo Rodrigues Freitas Carla Nágila Cordeiro Cláudia Goulart de Abreu Robson Mateus Freitas Silveira Silvana Cavalcante Bastos Leite

This study evaluated the effects of limestone particle size and 25-hydroxycholecalciferol supplementation on performance, egg quality, digestive organ biometrics, bone characteristics, thermoregulatory responses, and behavior of brown laying hens reared under hot environmental conditions. The trial lasted five periods of 28 days. A total of 270 Lohmann Brown Lite hens (48 weeks old) were allocated in a completely randomized design with a 2 × 2 + 1 factorial arrangement, comprising two limestone particle sizes (MGD 0.568 mm and MGD 1.943 mm) and two supplementation levels of vitamin D (2760 IU and 1380 IU), plus a control diet, totaling five treatments with six replicates each. The dietary treatments were as follows: (1) control diet without vitamin D supplementation; (2) 250 g vitamin D with 100% fine limestone; (3) 125 g vitamin D with 100% fine limestone; (4) 250 g vitamin D with 50% fine + 50% coarse limestone; and (5) 125 g vitamin D with 50% fine + 50% coarse limestone. Productive performance, egg quality, organ biometrics, bone traits, thermoregulatory variables, and behavioral indicators were measured. Data were analyzed by ANOVA, followed by Tukey test (5%), considering the factorial model. There was no interaction between the factors for any parameter evaluated. There was an effect of shift on thermoregulatory variables. The other variables were not influenced by the treatments. These findings indicate that the tested limestone particle sizes can be incorporated in the diets of brown laying hens without affecting performance, egg quality, bone integrity, thermoregulation, or behavior, regardless of vitamin D supplementation, under hot climatic conditions.

Poultry doi: 10.3390/poultry4040052

Authors: Beiwen Zhang Xiaobing Li Hongxi Li Chengzhen Weng Xinxin Huang Yuhang Jiang Longxin Qiu Hongbo Chen

Bidens pilosa L. extract (BPE), a traditional medicine known for its antimicrobial properties, has not been thoroughly investigated for its potential against avian pathogenic Escherichia coli (APEC), a major pathogen responsible for severe economic losses and high mortality in poultry. This study aimed to comprehensively assess the antibacterial activity of BPE against APEC through both in vivo and in vitro experiments and to explore its underlying mechanisms. In a chicken infection model, BPE treatment led to an 80% cure rate and 20% mortality, in contrast to the 90% diarrhea and 70% mortality observed in the untreated model group. BPE also significantly alleviated intestinal tissue damage and reduced serum levels of inflammatory cytokines IL-6 and IL-1β (p < 0.01). In vitro analyses revealed a minimum inhibitory concentration (MIC) of 625 mg/mL. BPE dose-dependently suppressed bacterial motility, swarming, and biofilm formation (p < 0.01) and markedly increased membrane permeability, indicated by elevated release of nucleic acids, proteins, and alkaline phosphatase (p < 0.001). Moreover, PCR results showed that treatment with BPE at 1/2 MIC for 24 h significantly downregulated multiple virulence-associated genes, including aatA, papC, ibeB, vat, ompA, iss, fyuA, and irp2 (p < 0.01). These results demonstrate that BPE exerts its anti-APEC effects by damaging cell membrane integrity, inhibiting biofilm formation and motility, and suppressing virulence gene expression. Our findings support the potential of BPE as a natural alternative for controlling APEC infections and contribute a scientific basis for the use of traditional herbal medicine in combating bacterial diseases.

Poultry doi: 10.3390/poultry4040051

Authors: Mohammad Nasim Sohail Srikrishna Isloor Doddamane Rathnamma S. Chandra Priya Belamaranahally M. Veeregowda Nagendra R. Hegde Csaba Varga Nicola J. Williams

The emergence of antimicrobial resistance (AMR) across the broiler production chain holds significant economic, animal, and public health implications. This study investigated phenotypic resistance to 13 antimicrobials and the presence of 35 antimicrobial resistance genes (ARGs) in Escherichia coli (n = 291) isolated across three broiler production chains (broiler breeder farms, hatcheries, commercial broiler farms, and retail meat shops). An extremely high phenotypic resistance (>70%) to doxycycline, ciprofloxacin, and cefpodoxime, and very high resistance (50–70%) to ampicillin, cefotaxime, gentamicin, and ceftazidime was observed. In addition, 97% of isolates were multidrug-resistant (resistant to ≥1 drug in ≥3 antimicrobial classes), 42% were extended-spectrum beta-lactamase (ESBL) producers, 65% were resistant to third-generation cephalosporins (3GCR), and 21% were resistant to colistin. The Poisson regression model revealed no significant difference in AMR among broiler production stages, except for colistin. Among 35 ARGs tested, 24 (67%) were detected at least once. The most prevalent were tetA, blaTEM, qnrB, qnrS, and aac(6′)-Ib-cr, while qnrD, sul2, blaOXA, and blaCTX-M were detected at lower levels (1–7%). All five tested mcr genes (mcr-1 to mcr-5) were identified in commercial farms and retail shops. No blaNDM, tetB, tetC, tetD, tetM, qnrC, aac(3)-IIa (aacC2), aph(3)-IIa (aphA2), or aac(6′)-Ib genes were found. A strong correlation was observed between AMR phenotypes and ARGs. High AMR among E. coli in broiler production poses significant One Health risks, with widespread MDR, ESBL production, and resistance to critically important antimicrobials. Prudent antimicrobial use, enhanced surveillance and education, farm biosecurity, and One Health strategies are crucial in mitigating these threats.

Poultry doi: 10.3390/poultry4040050

Authors: Thiago de Souza João Paulo Ferreira Rufino Pablo Garcia Dias Laiane Ferreira de Souza Kaisa Freitas de Araújo Maria Fernanda da Silva Gomes Maiko Willas Soares Ribeiro Francisco Alberto de Lima Chaves Philip Dalbert da Silva Castro Joel Lima da Silva Junior Marco Antonio de Freitas Mendonça Joana Maia Mendes Emerson Silva Lima Angela Maria Comapa Barros Carlos Alexandre Góes Farias Juliano Carneiro Ramos Ronner Joaquim Mendonça Brasil Felipe Dilelis de Resende Sousa Adriano Teixeira de Oliveira Suelen Miranda dos Santos Noedson de Jesus Beltrão Machado

The increasing demand for sustainable and cost-effective animal feed alternatives has stimulated the use of agro-industrial by-products in poultry diets. This study evaluated the effects of tambaqui (Colossoma macropomum) residual oil (TRO), derived from aquaculture waste, on productive performance, physiological responses, and egg quality in commercial laying hens. A total of 144 Hisex Brown hens were assigned to diets containing 0%, 1.5%, 3.0%, or 4.5% TRO for 63 days. While TRO inclusion did not affect overall productivity, moderate levels (1.5% and 3.0%) improved egg weight, yolk pigmentation, and internal quality (Haugh unit). Hematological and biochemical parameters indicated metabolic adaptations, with increased cholesterol and decreased triglycerides in treated groups. The yolk fatty acid profile revealed higher omega-3 content with TRO inclusion, but lipid oxidation (TBARS) also increased, especially at higher levels. Sensory evaluation showed reduced aroma and flavor acceptability in eggs from hens fed 3.0% and 4.5% TRO. These findings suggest that moderate TRO inclusion can enhance egg nutritional value and support sustainable aquaculture waste reuse, though excessive levels may compromise product acceptability. Optimal inclusion levels should be further explored to balance metabolic benefits, oxidative stability, and consumer preferences.

Poultry doi: 10.3390/poultry4040049

Authors: Sanjida Akter Giovana M. Longhini Md Saidul Haque Yuhua Z. Farnell Yuxiang Sun

Following restrictions on antibiotic growth promoters in poultry production, there is growing interest in natural feed additives that support health and productivity. Among these, black cumin (Nigella sativa) has emerged as a promising candidate due to its antioxidant, antimicrobial, and immunomodulatory properties. Most studies report that black cumin, in the form of whole seeds, seed meal, or seed oil, improves body weight gain and feed conversion ratio, enhances antioxidant and immune status, and provides additional benefits on lipid profiles, liver enzymes, and cecal microbial balance. This review provides a focused synthesis of recent studies (2014–2025) on black cumin supplementation in broiler chickens, considering its various forms (whole seeds, seed meal, seed oil, and nano-formulations) and production contexts (healthy, heat-stressed, and disease-challenged birds). Specifically, this review compares responses across different forms and doses, evaluates effects on growth performance, immune function, gut health, antioxidant status, liver metabolism, and meat and carcass quality, and highlights inconsistencies among studies. Additionally, it identifies key research gaps to guide future investigations, including optimal dosing, long-term safety, and practical applications in commercial production. Overall, black cumin shows potential as a natural alternative to antibiotics, but further standardized, large-scale studies are needed to confirm its efficacy and feasibility in sustainable poultry farming.

Poultry doi: 10.3390/poultry4040048

Authors: Deivid Kelly Barbosa Vivian A. R. C. Heiss Maria F. C. Burbarelli Leonardo O. Seno Rodrigo G. Garcia Rita T. R. Pietramale Fabiana R. Caldara

Animal welfare (AW) is increasingly being discussed and mandated in chicken production, both by current Brazilian legislation and by importing markets. Industries continually seek greater financial returns, and within this context, it has been observed that the proper implementation of animal welfare principles effectively reduces losses by minimizing carcass condemnations due to injuries, thereby significantly contributing to in-creased profitability. The economic impact of non-compliance with these welfare standards in broiler production is well documented in the scientific literature. However, the same level of concern is not observed regarding the financial impact on integrated producers, who supply the raw materials. The present study aims to systematically map, contextualize, quantify, and qualitatively analyze articles evaluating the implementation of animal welfare in industrial broiler production and its impact on the financial returns of producers and integrated companies. The primary descriptor used was “animal welfare.” To quantify the relevant articles, the Proknow-C method was applied, followed by a similarity analysis using VoSViewer® software version 1.6.19 for systematic content evaluation. Descriptor combinations were led by animal welfare, followed by broiler pro-duction, poultry production, slaughter, economy, and rural producers. Although a significant number of articles address AW, those focused exclusively on chicken production are far fewer, declining even more when carcass condemnations are considered. Only six studies included the descriptor “economic,” and just three included “producer.” The con-tent of these nine studies was systematically reviewed, with two excluded and seven selected for discussion. Among the seven analyzed studies, none specifically examined the economic impact of AW implementation for the producer, clearly highlighting a significant research gap.

Poultry doi: 10.3390/poultry4040047

Authors: Shijinaraj Manjankattil Dhananjai Muringattu Prabhakaran Anup Kollanoor Johny Claire Peichel Divek V. T. Nair Grace Dewi Jason Langlie Trevor J. Gould Annie M. Donoghue

This study determined the efficacy of in-feed supplementation of a medium-chain fatty acid, caprylic acid (CA), on the cecal colonization of multidrug-resistant (MDR) Salmonella Heidelberg (SH) and its effect on the cecal microbiome of commercial broilers. A total of 24, 4-week-old commercial Ross 708 chickens were randomly allocated to two replicates of four treatment groups in eight BSL2 isolators (3 birds/isolator): Negative control (NC), Positive Control (PC), Antibiotic group (AB), and caprylic acid (CA) groups. The birds received a Salmonella-free standard corn–soy-based diet, with the broilers in the AB receiving 50 g/ton bacitracin methylene disalicylate, and the CA group receiving caprylic acid (1% w/w), in feed from days 1 to 35. All birds, except those in the NC group, were challenged with ~3.7 log10 CFU of MDR SH/5 mL by crop gavage on day 29. Cecal samples were collected 7 days after the challenge for SH recovery by direct plating and enrichment, as well as for DNA extraction for 16S rRNA gene amplicon sequencing. Compared to the PC group, a 3.6 log10 CFU/g reduction in SH was observed in the CA group (p < 0.05). Although no significant effect of CA on cecal microbial composition was observed, a significant difference in taxonomic α- and β-diversities was observed in the AB. CA also resulted in significant differences in hub taxa compared to PC in the network association analysis, indicating a potential role for microbiome modulation in its mechanism of action.

Poultry doi: 10.3390/poultry4040046

Authors: Víctor Marambio Francisca Di Pillo Cecilia Baumberger Cristobal Oyarzún Pablo Galdames Tamara Palma Pedro Jimenez-Bluhm Javiera Cornejo Stacey Schultz-Cherry Christopher Hamilton-West

Backyard poultry systems (BPS) are the most widespread form of animal production worldwide, contributing to household economies and improving food availability. However, limited biosecurity measures and close human–animal interactions raise concerns regarding zoonotic disease transmission. In recent years, consumer-driven motivations have given rise to non-traditional BPS with differential attributes (BPS-DA), yet there is limited knowledge about their food production practices. This study aimed to characterize and compare practices across 25 BPS and 25 BPS-DA in the Metropolitan Region using surveys, interviews, and direct observations of egg collections and poultry slaughters. Eggs were the main animal product in both systems, with women primarily responsible for care. Poultry slaughter was reported exclusively in BPS (60%), generally performed under inadequate hygienic conditions and without veterinary oversight. These practices, (poultry slaughter, food production and handling), may considerably increase the risk of human exposure to zoonotic pathogens, such as avian influenza viruses. In contrast, BPS-DA prioritized birds as companion animals (60%), free-range rearing (68%), and hobby-based production (80%). While both systems showed limited biosecurity, significant differences were found in the use of dedicated footwear (p = 0.01; V = 0.35), egg collection sites (p = 0.04; V = 0.29), and refrigeration (p = 0.004; V = 0.41). Veterinary access was limited in both (32% in BPS; 44% in BPS-DA). These findings highlight critical gaps in health management and underscore the need for context-specific educational and regulatory strategies for safer backyard poultry production.

Poultry doi: 10.3390/poultry4040045

Authors: André Salvador Kazantzi Fonseca Diéssy Kipper Nilo Ikuta Vagner Ricardo Lunge

Fowl adenovirus (FAdV) can cause different poultry diseases with economic losses in the broilers and layers commercial farms. FAdV is currently classified into five species and 12 serotypes, disseminated in poultry flocks worldwide. The present study aimed to identify FAdV species and serotypes in Brazilian poultry farms. A total of 678 chicken flocks from the main Brazilian poultry-producing regions were evaluated for FAdV infection between 2020 and 2023. FAdV was detected by a real-time PCR targeting 52K gene and further genotyped by partial sequencing of the hexon gene followed by phylogenetic analyses. The results demonstrated that FAdV was detected in 72 flocks (10.6%). In 46 of these samples, FAdV species and serotypes could be identified, including three main species: Aviadenovirus ventriculi (FAdV-A = 15), Aviadenovirus gallinae (FAdV-D = 15) and Aviadenovirus hepatitidis (FAdV-E = 16). Phylogenetic analysis based on 173 partial hexon sequences (including sequences from this study, 44 previously sequenced in Brazil, and 86 data from other countries) revealed five separate clades for FAdV species. All Brazilian FAdVs were classified into the same three species reported above (FAdV-A = 19, FAdV-D = 34, FAdV-E = 37), and also in well-supported subclades for each serotype: FAdV-A1 (n = 19), FAdV-D9 (n = 1), FAdV-D11 (n = 33), FAdV-E6 (n = 1), FAdV-E8a (n = 33), FAdV-E8b (n = 3). Amino acid substitutions in the hyper variable regions (1, 2 and 3) and conserved motifs of the Hexon protein were further analyzed, enabling discrimination between closely related serotypes. This study demonstrates the circulation of different FAdVs in Brazil, highlighting FAdV-A1, FAdV-D9, FAdV-D11, FAdV-E6, FAdV-E8a and FAdV-E8b. The findings reported here also indicate genetic and amino acid diversity in the Hexon protein of the FAdVs in Brazilian poultry farms, which are of importance for molecular surveillance and poultry diseases control strategies.

Poultry doi: 10.3390/poultry4040044

Authors: Bereket Dessalegn Motuma Debelo Michael Hess Wageha A. Awad

The interaction between gut microbiota and C. jejuni in the guts of broiler chickens is essential for the bacterium’s growth and potential pathogenicity. Recent findings highlighted the significance of modifying gut microbiota in relation to higher C. jejuni colonization rates and improved immune responses. This study suggested that a varied and balanced microbiota aids in decreasing and preventing C. jejuni proliferation via mechanisms including competitive exclusion, the synthesis of antimicrobial peptides, and the modulation of the chicken immune response. C. jejuni demonstrates adaptability in the gut environment by encouraging the growth of beneficial bacteria while inhibiting others, improving the way it acquires nutrients, and modifying the transcriptional response of its virulence factors. The dynamic nature of these microbiota communities has caused differences in the results of how gut microbiota and C. jejuni proliferation interact. Understanding the relationships between gut microbiota and C. jejuni is critical for developing strategies to mitigate the impact of C. jejuni in broiler chickens. This review compiles information on the relationships between gut microbiota and C. jejuni proliferation in broiler chickens and offers commentary on how the findings could improve gut health and food safety.

Poultry doi: 10.3390/poultry4040043

Authors: Tommaso Bergamasco Aurora Ambrosi Vittoria Tregnaghi Rachele Urbani Giacomo Nalesso Francesca Menegon Angela Trocino Mattia Pravato Francesco Bordignon Stefania Sparesato Grazia Manca Guido Di Martino

Keel bone lesions (KBLs) represent a relevant welfare concern in laying hens, arising from complex interactions among genetics, housing systems, and management practices. This study presents the development of an image analysis system for the automated detection and classification of KBLs in slaughterhouse videos, enabling scalable and retrospective welfare assessment. In addition to lesion classification, the system can track and count individual carcasses, providing estimates of the total number of specimens with and without significant lesions. Videos of brown laying hens from a commercial slaughterhouse in northeastern Italy were recorded on the processing line using a smartphone. Six hundred frames were extracted and annotated by three independent observers using a three-scale scoring system. A dataset was constructed by combining the original frames with crops centered on the keel area. To address class imbalance, samples of class 1 (damaged keel bones) were augmented by a factor of nine, compared to a factor of three for class 0 (no or mild lesion). A YOLO-based model was trained for both detection and classification tasks. The model achieved an F1 score of 0.85 and a mAP@0.5 of 0.892. A BoT-SORT tracker was evaluated against human annotations on a 5 min video, achieving an F1 score of 0.882 for the classification task. Potential improvements include increasing the number and variability of annotated images, refining annotation protocols, and enhancing model performance under varying slaughterhouse lighting and positioning conditions. The model could be applied in routine slaughter inspections to support welfare assessment in large populations of animals.

Poultry doi: 10.3390/poultry4030042

Authors: Tam T. Tran Niamh Caffrey Haskirat Grewal Yuyu Wang Rashed Cassis Chunu Mainali Sheryl Gow Agnes Agunos Sylvia Checkley Karen Liljebjelke

Enterococci, commonly found in the normal intestinal flora of humans and animals, have emerged as an important human pathogen. A total of 184 isolates (88 isolates in 2015 and 96 isolates in 2016) were collected from 46 flocks. Two predominant enterococcus species were identified: Enterococcus faecalis (59%) and Enterococcus faecium (~39%). Resistance to penicillin was significantly decreased in the overall enterococci community, while it remained unchanged in the multi-class drug resistant (MDR) community. We identified the emeA and efrAB genes, which encode efflux pump systems, in 93% (26/28) of the MDR isolates with (intermediate) resistance to levofloxacin. The ermB gene was present in all MDR strains with resistance to erythromycin. The lsa gene was detected in 87% (84/97) of the MDR isolates with resistance to quinupristin/dalfopristin. About 82.2% of MDR strains in 2015 and 100% of MDR strains in 2016 carried the insertion sequence IS256, which is known to be associated with AMR genes, conferring resistance to erythromycin, gentamicin and vancomycin in enterococci. These results support the need for monitoring AMR in Gram-positive bacteria in poultry production, specifically in broiler chicken farms, to complement current AMR data, and develop a timely intervention framework.

Poultry doi: 10.3390/poultry4030041

Authors: Marko Tukša Stephen C. Mansbridge Michael R. Bedford Stephen P. Rose Vasil R. Pirgozliev

A 28-day study involving 448 male Ross 308 broilers aimed to determine the effect of dietary rice bran (RB) and xylanase (XYL) in maize- and wheat-based diets on chicken growth, N-corrected apparent metabolizable energy (AMEn), and nutrient availability. Two isonitrogenic and isocaloric maize- or wheat-based basal diets (BDs) were formulated matching breeding recommendations. Each diet was then split in four parts: two parts BD was substituted with 75 g/kg RB and then one of the RB substituted and one of the original parts was supplemented with 16,000 XYL units/kg, resulting in a total of eight experimental dietary treatments. Each diet was fed to seven pens of eight birds per pen following randomization. The data were analyzed by ANOVA using a 2 × 2 × 2 factorial design (cereal type × RB × XYL). Enzyme supplemented RB-free wheat-based diet had greater AMEn (p = 0.002) and fiber digestibility (p = 0.007) compared to the rest. Feeding RB reduced daily feed intake (p = 0.015) and weight gain (p < 0.001) of chicks. Birds fed wheat-based diets had greater feed efficiency, coupled with an increase in starch digestibility (SD) and energy conversion ratio (ECR). The observed differences in feed efficiency were explained only by SD and ECR.

Poultry doi: 10.3390/poultry4030040

Authors: Thiruvenkadan Aranganoor Kannan Srinivasan Palani Saravanan Ramasamy Sivakumar Karuppusamy Sunday Olusola Peters Malarmathi Muthusamy

Newcastle Disease (ND) is an important and notable disease among the avian infectious diseases, because of its high contagiousness, and the most virulent strains of ND virus (NDV) have impacted poultry breeders all over the world. Immunization and biosecurity measures are used to reduce ND; however, vaccination has been shown to offer protection against clinical signs but not against virus proliferation and shedding, which could have an adverse effect on the environment. The genetic basis for inherent resistance to NDV has been established, and genetic selection on existing resistance-related genetic variation can help to mitigate virus propagation. Further, understanding the genes and processes that drive the response to NDV will lay the groundwork for genetic improvement in poultry. The majority of studies on NDV susceptibility make use of phenotypic indicators such as body weight, morbidity, mortality, antibody response, and viral load. According to recent advancements in molecular genetic research, many different genes are diversely regulated in different chicken lines to NDV infection, which might be used in the future to establish disease-resistant breeding approaches. It is possible that many more genes linked to illness and resistance are still to be discovered, because the precise mechanism of resistance is not entirely understood. The enhanced genetic knowledge of chickens and the development of more advanced transgenic techniques would lead to pathogen resistance. Hence, this paper summarizes the current understanding of genetic resistance to Newcastle Disease, and we additionally highlight a few possible genes/markers connected with NDV that may improve chicken resistance to NDV infections and can be used to produce NDV-resistant chicken breeds/strains in the near future.

Poultry doi: 10.3390/poultry4030039

Authors: Lena Sonnenschein-Swanson Silvia Baur-Bernhardt Annemarie Käsbohrer Marcus Georg Doherr Diana Meemken Petra Weiermayer

Antimicrobial resistance (AMR) constitutes a serious public health issue, and the European Union (EU) requires reduction in the sales of antibiotics in farmed animals of 50% by 2030. A scoping review was conducted in PubMed for the years from 2000 to 2024, limited to the English and German languages, with the aims to (1) provide an overview of factors on commercial poultry farms potentially associated with health-related endpoints such as mortality, disease prevalence, carcass condemnation, performance as well as AMR/antimicrobial usage at different hierarchical levels (animal, flock/batch, stable, farm), and (2) identify inconsistencies with respect to these potential risk factors. Overall, 34 peer-reviewed publications met the inclusion criteria for the review. Significant associations identified in the uni- or multivariable statistical analysis were summarised using graphs and bar charts. The results highlight that risk factor–outcome associations often are complex, inconsistent with regards to the direction of the influence especially for some ordinal or categorical variables. In some associations such as the sex of the animals and performance, contrary directions were reported in different studies—illustrating the multifactorial dynamics of commercial poultry production. This research enhances the understanding of the complexity of commercial poultry production, which is essential when designing future studies and interpreting their results.

Poultry doi: 10.3390/poultry4030038

Authors: Natalia Coimbra da Silva Irenilza de Alencar Nääs Juliana de Souza Granja Barros Daniella Jorge de Moura

Understanding how environmental conditions affect broiler comfort across different seasons is crucial for enhancing welfare in commercial poultry production. This study aimed to identify the relationship between housing environment, litter conditions, and broiler discomfort at different growth stages using data collected from two flocks reared during winter and summer. Environmental variables (temperature, humidity, ammonia, pH, and CO2) and broiler responses were recorded and analyzed weekly. Discomfort was defined as a binary variable based on threshold deviations in temperature and air quality. Non-parametric statistical tests and a Random Forest model were employed to explore associations and predict comfort status. Results showed that discomfort was significantly higher during winter, particularly in weeks 1 and 6, likely due to thermal instability and rising ammonia levels. Summer flocks exhibited more stable comfort profiles. The predictive model achieved a high test accuracy (97.1%) and identified broiler weight, ammonia, and temperature as the strongest predictors of discomfort. Weekly discomfort patterns and feature importance analyses revealed critical intervention points and variables. These findings provide actionable insights for automating welfare monitoring in commercial broiler production, offering valuable information for season-specific management strategies and demonstrating the potential for integrating predictive models into automated welfare monitoring systems to support precision livestock farming.

Poultry doi: 10.3390/poultry4030037

Authors: Seyed Abolghasem Fatemi Edgar David Peebles

Optimal commercial conditions have been shown to improve the performance and meat yield of broilers. Also, dietary 25-hydroxycholecalciferol (25OHD3; crystalline form) has not shown a negative impact on chicken health when it was fed at 10 times (10×) higher than 69 μg/kg. The objectives of this study were to determine the effects of up to 8 times (8×) higher than the commercial level (69 μg/kg of feed) of dietary 25OHD3 on the performance, breast meat yield, and serum 25OHD3 concentration of broilers. Eighteen male chicks were randomly assigned to each of 20 pens within each of the two dietary treatments. Treatments were commercial diets containing 250 IU/kg of vitamin D3 (control) for the starter [(0 to 14 days post-hatch (poh), grower (15 to 28 poh), and finisher (29 to 42 poh) dietary phases; or diets containing Hy-D (water-soluble source of 25OHD3) that consisted of 552 (8×) μg/kg of 25OHD3 for the starter, 276 (4×) μg/kg of 25OHD3 for the grower, and 34.5 (0.5×) μg/kg of 25OHD3 for the finisher dietary phases. Live performance variables as well as serum 25OHD3 concentrations were measured in each dietary phase. At 14, 28, and 39 poh, breast meat yield that included pectoralis major (P. major) and pectoralis minor (P. minor) muscle weights was determined in ten replications per dietary treatment. Breast yield was also calculated by adding the values of the P. major and P. minor muscles. From 14 to 42 poh, the Hy-D diets decreased (p < 0.0001) broiler body weight (BW) and BW gain and increased (p < 0.0001) total mortality and feed conversion ratio in comparison to control treatment groups. In addition, birds fed Hy-D diets had significantly (p < 0.0001) lower P. major and breast meat yields from 14 to 39 poh as compared to those birds fed the control diet. Serum 25OHD3 concentration was significantly (p < 0.0001) higher (10×) in birds that belonged to the Hy-D diet treatment than those in the control diet treatment group. These results indicate that the disproportionally high (8×) level of dietary 25OHD3 resulted in detrimental effects on the performance and meat yield of broilers. A reduction in both performance and meat yield of broilers in response to the elevated level of dietary 25OHD3 may have been due to vitamin D3 toxicity, which can result in an association with the overproduction of the active form of the vitamin in response to elevated serum concentrations of 25OHD3.

Poultry doi: 10.3390/poultry4030036

Authors: Jill R. Domel Gregory S. Archer

To determine if exposing embryos to light during incubation affects antibody titer and corticosterone immediately following hatch, we incubated layer eggs and exposed them to light or darkness and vaccinated a subset of each treatment against Newcastle Disease Virus (NDV) using in ovo administration on ED 18, spray application at hatch (d 0), or not at all. There were six treatments: light incubated and non-vaccinated (LNV), light incubated and in ovo vaccinated (LIV), light incubated and post-hatch vaccinated (LPHV), dark incubated and non-vaccinated (DNV), dark incubated and in ovo-vaccinated (DIV), and dark incubated and post-hatch vaccinated (DPHV). Plasma corticosterone (CORT) and NDV antibody titers were measured on d 0, 7, and 14. Light-incubated chicks had lower (p < 0.05) plasma CORT on d 0. NDV titers did not differ (p > 0.05) between light- and dark-incubated chicks on d 0, 7, or 14. However, LIV chicks had higher antibody titers than LPHV on d 14. Exposing embryos to continuous green light during incubation may reduce stress during the early post-hatch period. Vaccination method, rather than exposure to continuous green light during incubation, may have a greater impact on humoral immune response post-hatch.

Poultry doi: 10.3390/poultry4030035

Authors: Gabriela Miotto Galli Ines Andretta Camila Lopes Carvalho Aleksandro Schafer da Silva Marcos Kipper

(1) Background: The goal of the present study was to evaluate whether the supplementation with a multi-species probiotic in the diet of laying hens can change the microbiota and health status of the oviduct. (2) Methods: A total of 60 cages housing lightweight laying hens (36 weeks old) were randomly assigned to the following two different treatments: a control group fed a diet without probiotic, and a treatment group receiving diets supplemented with 50 g/ton of probiotics. The trial lasted for 26 weeks, after which five layers were slaughtered per treatment for oviduct (magnum) assessment, focusing on microbiome composition, oxidant and antioxidant status, and morphological analyses. Additionally, intestinal (jejunum) samples were collected to determine oxidant and antioxidant status. (3) Results: Probiotic supplementation resulted in lower counts of organisms from the RB41 order (p = 0.039) and Burkholderia genus (p = 0.017), and a total reduction in Bacillus and Corynebacterium (p = 0.050) compared to the control treatment. Genera Burkholderia (p = 0.017), Corynebacterium (p = 0.050), and Bacillus (p = 0.050) were also lower with the probiotic supplementation in relation to the control. Genera Epulopiscium (p = 0.089), Flavobacterium (p = 0.100), Ruminococcus (p = 0.089), and Staphylococcus (p = 0.100) tended to be lower in the probiotic group compared to the control. No significant differences were found between treatments for oviduct lesions. Probiotic treatment resulted in a higher protein thiol level in the intestine compared to the control (p < 0.001). However, the use of probiotics tended to reduce glutathione S-transferase levels in the oviduct compared to the control (p = 0.068). (4) Conclusions: These results suggest that dietary supplementation with probiotics can modulate the oviduct microbiota and improve the antioxidant status of laying hens, without causing tissue damage. Further research is warranted to explore the long-term implications of these changes on reproductive performance and egg quality.

Poultry doi: 10.3390/poultry4030034

Authors: Samin Dahal Xiao Yang Bidur Paneru Anjan Dhungana Lilong Chai

Foraging behavior in hens is an important indicator of animal welfare. It involves both the search for food and exploration of the environment, which provides necessary enrichment. In addition, it has been inversely linked to damaging behaviors such as severe feather pecking. Conventional studies rely on manual observation to investigate foraging location, duration, timing, and frequency. However, this approach is labor-intensive, time-consuming, and subject to human bias. Our study developed computer vision-based methods to automatically detect foraging hens in a cage-free research environment and compared their performance. A cage-free room was divided into four pens, two larger pens measuring 2.9 m × 2.3 m with 30 hens each and two smaller pens measuring 2.3 m × 1.8 m with 18 hens each. Cameras were positioned vertically, 2.75 m above the floor, recording the videos at 15 frames per second. Out of 4886 images, 70% were used for model training, 20% for validation, and 10% for testing. We trained multiple You Only Look Once (YOLO) object detection models from YOLOv9, YOLOv10, and YOLO11 series for 100 epochs each. All the models achieved precision, recall, and mean average precision at 0.5 intersection over union (mAP@0.5) above 75%. YOLOv9c achieved the highest precision (83.9%), YOLO11x achieved the highest recall (86.7%), and YOLO11m achieved the highest mAP@0.5 (89.5%). These results demonstrate the use of computer vision to automatically detect complex poultry behavior, such as foraging, making it more efficient.

Poultry doi: 10.3390/poultry4030033

Authors: Angélica Maria Angelim Silvana Cavalcante Bastos Leite Angela Maria de Vasconcelos Angefferson Bento Evangelista Carla Lourena Cardoso Macedo Lourenço Maria Rogervânia Silva de Farias Cláudia Goulart de Abreu Robson Mateus Freitas Silveira

The objective of this study was to evaluate the effect of two limestone granulometries (0.568 and 1.943 mm) and different levels of vitamin D3 (12.5 g and 25 g) on the thermoregulatory and behavioral responses of replacement pullets. Lohman brown lineage pullets (270 birds), with an average weight of 639.60 g ± 6.05 and an initial age of eight weeks, were used in this study. The experimental design adopted was completely randomized in a 2 × 2 × 2 + 1 factorial arrangement (2 limestone granulometries × 2 levels of vitamin D3 × 2 shifts). The respiratory rate (RR), cloaca temperature (CT), feather surface temperature (FST) and featherless surface temperature (FLST) were higher in the afternoon (p < 0.05), while the thermal gradient (TG) was higher in the morning (p < 0.05). Birds supplemented with different limestone granulometries and different levels of vitamin D3 showed similar thermoregulatory and behavioral responses. The “eating” activity was more frequent in the morning, while in the afternoon, the birds remained seated for longer (p < 0.05). The dietary supplementation with different limestone granulometries and vitamin levels did not impair thermoregulation even at higher temperatures. Regardless of the level of vitamin D3, they showed a better expression of welfare-related behavioral activities in the morning in the semiarid region.

Poultry doi: 10.3390/poultry4030032

Authors: Chloe M. O’Brien Frank W. Edens

Environmentally modified housing [EMH; windowless, insulated sidewalls and ceiling, thermostatically controlled ventilation fans) versus conventional housing [CVH; cross-ventilated, insulated ceiling, ceiling fans) improved broiler performance in the summer. The objective of this investigation was to determine whether social behaviors differed between two population densities (0.06 m2/chick [HD] or 0.07 m2/chick [LD]) in these houses. We used a randomized block statistical design, involving houses, population densities, observation times, and bird age. Behaviors were observed weekly, during the morning and the afternoon. Individual observers focused on the group of broilers in one of three defined 26.76 m2 areas in each of the four pens in each house. Aggressive encounters, tail and back pecking, feather eating, thermoregulatory, preening, and flock mobility were recorded. Feather pecking, eating and aggressive encounters were expressed at greater rates in HD birds in CVH. A salt-deficient diet caused increased feather pecking and aggressive encounters, which decreased after correction of the mistake. Increased heat indices (HIs), HD, and greater light intensity in CVH influenced behaviors and mortality more severely than in EMH. In CVH and EMH, burrowing/thermoregulatory/resting activity increased with increasing HIs. Afternoon preening was elevated significantly in EMH. It was concluded that broilers reared in EMH were more comfortable and experienced improved welfare compared to those reared in CVH.

Poultry doi: 10.3390/poultry4030031

Authors: Elyse Mosco David Kilroy Arun H. S. Kumar

Background: Reliable and non-invasive methods for assessing welfare in poultry are essential for improving evidence-based welfare monitoring and advancing management practices in commercial production systems. The iris-to-pupil (IP) ratio, previously validated by our group in primates and cattle, reflects autonomic nervous system balance and may serve as a physiological indicator of stress in laying hens. This study evaluated the utility of the IP ratio under field conditions across diverse commercial layer housing systems. Materials and Methods: In total, 296 laying hens (Lohmann Brown, n = 269; White Leghorn, n = 27) were studied across four locations in Canada housed under different systems: Guelph (indoor; pen), Spring Island (outdoor and scratch; organic), Ottawa (outdoor, indoor and scratch; free-range), and Toronto (outdoor and hobby; free-range). High-resolution photographs of the eye were taken under ambient lighting. Light intensity was measured using the light meter app. The IP ratio was calculated using NIH ImageJ software (Version 1.54p). Statistical analysis included one-way ANOVA and linear regression using GraphPad Prism (Version 5). Results: Birds housed outdoors had the highest IP ratios, followed by those in scratch systems, while indoor and pen-housed birds had the lowest IP ratios (p < 0.001). Subgroup analyses of birds in Ottawa and Spring Island farms confirmed significantly higher IP ratios in outdoor environments compared to indoor and scratch systems (p < 0.001). The IP ratio correlated weakly with ambient light intensity (r2 = 0.25) and age (r2 = 0.05), indicating minimal influence of these variables. Although White Leghorn hens showed lower IP ratios than Lohmann Browns, this difference was confounded by housing type; all White Leghorns were housed in pens. Thus, housing system but not breed was the primary driver of IP variation. Conclusions: The IP ratio is a robust, non-invasive physiological marker of welfare assessment in laying hens, sensitive to housing environment but minimally influenced by light or age. Its potential for integration with digital imaging technologies supports its use in scalable welfare assessment protocols.

Poultry doi: 10.3390/poultry4030030

Authors: Fernanda Danieli Antoniazzi Valentini Heloísa Pagnussatt Fernanda Picoli Letieri Griebler Carine de Freitas Milarch Arele Arlindo Calderano Fernando de Castro Tavernari Tiago Goulart Petrolli

The objective of this study was to validate the energy matrix of guanidinoacetic acid (AGA) in broiler diets, assessing its effects on performance, carcass traits, organ development, and meat quality. The experiment was conducted at the UNOESC Xanxerê poultry facility using 480 COBB broilers in a completely randomized design with three treatments: positive control (standard energy level), negative control (75 kcal/kg reduction in metabolizable energy—ME), and negative control + AGA (600 mg/kg). Male broilers in the positive control and negative control + AGA groups showed improved feed conversion, higher weight gain, and greater feed intake (p < 0.001) compared to the negative control group. A significant difference in relative liver weight (p = 0.037) was observed between the positive and negative control groups. Birds supplemented with AGA had higher blood glucose levels and lower levels of cholesterol (p = 0.013), triglycerides (p = 0.005), total proteins (p < 0.001), and creatinine (p = 0.056). Regarding meat quality, the AGA-supplemented group showed higher crude protein content and greater lipid peroxidation in breast meat. In conclusion, the inclusion of AGA using an energy matrix reduced by 75 kcal/kg ME is feasible, maintaining performance and carcass characteristics while improving meat quality in broiler chickens.

Poultry doi: 10.3390/poultry4030029

Authors: Maria Papageorgiou Ouranios Tzamaloukas Panagiotis Simitzis

Nowadays, consumers are becoming increasingly concerned about the husbandry conditions under which animals are raised, particularly broilers, since broilers are one of the species whose welfare is most impaired in intensive farming systems. One of the primary means of communicating husbandry practices to consumers is through product labelling. Thus, a rising number of animal welfare labelling schemes for broilers are being developed and used across Europe by initiatives of both public and private stakeholders, including NGOs that advocate for animal welfare. This review aims to identify, analyze, and compare these labelling schemes with a focus on the main animal welfare provisions included in them, which contribute to enhanced animal welfare. The schemes were identified through web searches, so that we could visit their official websites, access their standards and regulations and study them in detail. We included in our research only those schemes whose criteria were publicly available. In total, 16 schemes were selected and analyzed. Although these schemes vary in their criteria, they all enhance the welfare standards of broiler production, primarily through incorporating environmental enrichment and/or access to the outdoors. Most schemes define and specify in detail the required animal welfare provisions, setting a clear application frame for the raising period of the birds. However, the welfare of animals during transport and slaughter is often overlooked.

Poultry doi: 10.3390/poultry4030028

Authors: Benjamin N. Alig Kenneth E. Anderson Dimitri M. Malheiros Kari L. Harding Ramon D. Malheiros

Stocking density is one of the major concerns in all production systems, which is why lawmakers, retailers, and consumers are increasingly concerned about this issue and its relation to animal welfare. The aim of this study was to identify if stocking density had an effect on white egg layer production, egg quality, bird health, and welfare parameters. For this study, five stocking densities were evaluated in colony cages: 1342 cm2/hen, 897 cm2/hen, 671 cm2/hen, 535 cm2/hen, and 445 cm2/hen. Egg production and physical egg quality were measured. Hen health and welfare parameters including corticosterone levels, H/L, oxidative stress pathways, jejunum tight junction protein expression, bone health, gut histology, body condition, and cytokine expression were evaluated. The results from this indicated that higher stocking densities resulted in lower production but larger eggs, while feed efficiency remained unaffected. Furthermore, physical egg quality parameters also remained unaffected. When stress and welfare parameters were analyzed, this research identified that decreasing stocking density did not affect jejunum oxidative stress pathways, pro-inflammatory cytokine expression, bone health, or intestinal health. At the final sampling period (69 weeks), the highest stocking density demonstrated higher corticosterone concentrations and IL-10 expression compared to the lowest stocking density. Furthermore, feather scores were found to be poorer as density increased. Finally, the highest density had higher Hansen’s test scores compared to other densities, which indicates a greater fear response. In conclusion, it appears that decreasing stocking density may provide some benefits in production and welfare to commercial egg layers, particularly at the end of the laying cycle.

Poultry doi: 10.3390/poultry4030027

Authors: Benjamin N. Alig Kenneth E. Anderson Ramon D. Malheiros

The amount of space provided to laying hens has been an animal welfare topic of concern from consumers, special interest groups, and lawmakers. The freedom to perform normal behaviors is one component of animal welfare, and, therefore, the objective of this study was to assess behavior at different stocking densities. Shaver White laying hens were housed in colony cages at five stocking densities. Video recordings of three cages/treatment were taken at 30, 46, and 62 weeks of age in the morning, afternoon, and night. At each age, a 20 min segment of video from each time of day was analyzed. Every minute was annotated to identify the behavior that hens spent the majority of their time performing. Data were averaged to calculate the percentage of hens engaged in each behavior per cage. The total count of aggressive bouts was recorded across the 20 min period. Data were analyzed with a general linear model utilizing the variables time of day, density, age, and the full factorial of interactions. Intermediate stocking densities displayed the lowest percentage of crouching (p = 0.009) and aggressive acts per hen (p < 0.0001). Hens stocked at 1341.93 cm2 walked the most (p < 0.0001). Hens were seen standing and preening (p < 0.0001) more in the morning, crouching and sham dust bathing (p < 0.0001) more in the afternoon, stretching less while feeding and drinking, and being more aggressive at night (p < 0.0001). Finally, as hens aged, they began to stand and crouch more (p < 0.0001) and preen (p = 0.013), walk (p < 0.0001), and demonstrate aggressive behaviors (p = 0.007) less. In conclusion, the majority of behaviors assessed were not influenced by stocking density. However, the different amounts of aggression between the treatments could indicate higher stress and frustration, which warrants more investigation.

Poultry doi: 10.3390/poultry4020026

Authors: Gert Coertze Rene Kwakkel Laura Star Christine Jansen van Rensburg

Limited published data areavailable on the current DLys requirements of Hy-Line Silver-Brown layers. The effects of energy (AMEn) and standardized ileal digestible lysine (DLys) concentration on the performance of Hy-Line Silver-Brown layers were studied from 20 to 35 weeks of age. The experimental design was randomized with twenty-four dietary treatments arranged as a 2 × 12 factorial with two AMEn concentrations (2750 and 2900 kcal/kg feed) and twelve levels of DLys (4.2, 4.5, 4.8, 5.1, 5.4, 5.7, 6.0, 6.6, 6.3, 6.9, 7.2, and 7.5 g/kg). Total egg weight (TEW), average egg weight, total egg number (TEN), laying rate, total feed intake, average daily feed intake (ADFI), mortality, hen body weight, hen body weight gain, eggshell thickness, eggshell breaking strength, yolk weight, albumen weight, and eggshell weight were recorded. An increase in energy content from 2750 to 2900 kcal AMEn/kg reduced ADFI (p < 0.001), egg mass output (p = 0.042), and feed conversion ratio (p = 0.018, g/g; p = 0.001, g/dozen) and increased the fat percentage in the liver (p = 0.028). An increased DLys intake from 529 to 882 mg/hen/day increased the TEN (p = 0.001), TEW (p < 0.001), and egg mass output (p < 0.001); improved the feed conversion ratio (p < 0.001); and reduced carcass (p = 0.001) and liver fat percentage (p = 0.05). Hy-Line Silver-Brown hens require no more than 780 mg (optimized egg production) and 880 mg (maximized egg weight) DLys/hen/day during pre-peak and peak production phases.

Poultry doi: 10.3390/poultry4020025

Authors: Jean Kaique Valentim Alexander Alexandre de Almeida Felipe Cardoso Serpa Maria Fernanda de Castro Burbarelli Gisele Aparecida Felix Kaique Moreira Gomes Caio Cesar dos Ouros Fabiana Ribeiro Caldara Sílvia Maria Martelli Claudia Marie Komiyama Rodrigo Garófallo Garcia

This study evaluated the effects of natural pigments, such as paprika extract and marigold flower extract, on performance, egg quality, carotenoid content in the yolk, and shelf life of Japanese quail eggs. The experiment included 160 birds, divided into 4 treatment groups, as follows: 0.8% paprika extract, 0.8% marigold flower extract, 0.8% paprika/marigold (P/M) mixture, and a control group. The experiment lasted 84 days. The inclusion of paprika, marigold, or their combination did not affect performance parameters, except for feed conversion, which was significantly poorer in the supplemented groups compared to the control. An improvement in yolk color was observed, particularly in the marigold group, which showed higher concentrations of β-carotene (40 g/kg). Yolk color intensity, measured using the L*, a*, and b* scales, was enhanced in all supplemented groups. During storage, yolk weight increased after 5.72 days, while albumen weight showed a significant reduction starting at 4.30 days, with a more pronounced decrease after 6.6 days. Albumen diameter expanded after 15.7 days of storage, and the Haugh unit was significantly affected from the 17th day onward. Yolk percentage decreased after 4.06 days, while albumen and eggshell percentages decreased after 4.10 and 3.41 days, respectively. These results suggest that paprika and marigold extracts are effective in improving yolk color and maintaining egg quality without compromising performance. However, a poorer feed conversion by mass was observed in the groups fed with the paprika, marigold, and the (P/M) mixture, compared to the control group. These natural pigments also positively impacted egg quality, particularly in terms of color intensity and internal parameters, and helped maintain egg quality during storage, meeting consumer expectations for high-quality products. Future studies should focus on evaluating the antioxidant effects of these pigments in eggs, as this could provide a deeper understanding of their potential benefits, both in terms of nutritional quality and shelf-life enhancement.

Poultry doi: 10.3390/poultry4020024

Authors: Joyce de Jesus Mangini Furlan Melina Lima Santos Silvia Helena Seraphin de Godoy Ricardo Luiz Moro de Sousa

The application of chemical additives in poultry litter management aims to control the microbial population and reduce harmful gases. We conducted in vitro analyses to determine and compare the minimum inhibitory concentration (MIC) of commercial chemical additives of calcium oxide, aluminum sulphate, and copper sulphate on bacteria such as Salmonella Enteritidis, Salmonella Infantis, Salmonella Heidelberg, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa; yeast (Candida albicans); and fungi (Aspergillus flavus and Penicillium citrinum). The minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) were also evaluated. Chemical additive solutions were prepared at a concentration of 0.1 g/mL and diluted up to 0.00078 g/mL, corresponding to concentrations from 10 kg/m2 to 0.07 kg/m2 when the additives were applied to the litter. In general, aluminum sulphate inhibited the growth of bacterial and fungal strains at a concentration of 0.62 kg/m2 (6.25%). On the other hand, additives based on copper sulphate and calcium oxide showed an inhibitory effect on bacterial and fungal strains at dosages above 2.5 kg/m2 and 5 kg/m2, respectively. Research into commercially available poultry products is rare but important for determining the correct dosage of chemical additives to control the microbial and fungal population of poultry litter. The use of a correct dosage can prevent microbial resistance to chemical additives. This study continues to analyze the use of additives on commercial farms.

Poultry doi: 10.3390/poultry4020023

Authors: Zineb Soubai Nadia Ziyate Sami Darkaoui Rim Rais Siham Fellahi Benaissa Attarassi Nabila Auajjar

Monitoring Campylobacter and antimicrobial resistance is critical, as its presence in the food chain, particularly in poultry, represents a serious threat to public health. However, despite its significant impact, this bacterium remains largely underestimated and under-surveilled in many countries, including Morocco. The current study aims to understand the occurrence of Campylobacter spp. in different poultry production systems, highlighting the importance of continuously monitoring antimicrobial susceptibility in these bacteria. For this purpose, 300 poultry samples were collected from a slaughterhouse and 254 from traditional markets in the Rabat-Salé-Kénitra region. The research on Campylobacter was performed according to the standard ISO10272-1(2017), and the confirmation of Campylobacter species was carried out using MALDI-TOF mass spectrometry. Additionally, the disk diffusion method was employed to assess antimicrobial susceptibility, and conventional PCR was utilized to detect the presence of the tet(O) gene in tetracycline-resistant strains. Out of 554 samples collected, 159 (28.7%) tested positive for Campylobacter, of which 84% were identified as Campylobacter coli and 16% as Campylobacter jejuni. Moreover, the results revealed a notably higher detection of Campylobacter in traditional markets (41.33%) than in slaughterhouses (19.85%). Additionally, it was more prevalent in chicken samples (35.37%) than in turkey samples (22.02%). Campylobacter resistance to antimicrobials revealed a resistance rate of 99% to ciprofloxacin, 73% to ampicillin, 82% to tetracycline, 29% to erythromycin, and 0% to gentamicin, as well as to the association of amoxicillin and clavulanic acid. Among the strains with a phenotypic resistance profile to tetracycline, 80% carried the tet(O) gene. The results provide an overview of the current state of antibiotic resistance in Campylobacter in Morocco. They underline the urgent need for the prudent use of antimicrobials and may encourage further research into the development of new antimicrobial agents. They also highlight the importance of raising awareness of the risk of carcass contamination

Poultry doi: 10.3390/poultry4020022

Authors: Isobel M. Whiting Stephen P. Rose Ahmed M. Amerah Vasil R. Pirgozliev

A study was conducted using 144 Hy-Line Brown laying hens (22 weeks old) to assess the impact of exogenous enzymes on energy utilisation and ileal nutrient digestibility in diets containing 300 g/kg wheat distillers’ dried grains with solubles (DDGS). A basal diet was prepared and divided into eight treatments: a control (C) and diets supplemented with 2000 units/kg xylanase (XYL), 500 units/kg phytase (PHY), and 4000 units/kg protease (PRO), individually and in combination. The diets were fed for nine days to six coops, each housing three birds. Feed intake, weight gain, and feed conversion ratio were recorded. The feed and excreta were analysed for gross energy, and the apparent metabolisable energy (AME) was calculated. On the final day, the birds were euthanised, and ileal digesta were collected, freeze-dried, and analysed for the digestibility coefficients of dry matter (DM), nitrogen, fat, and neutral detergent fibres (NDFs). XYL supplementation improved (p = 0.035) dietary AME but did not affect (p > 0.05) DM, nitrogen, fat, or NDF digestibility. No significant effects (p > 0.05) were observed for PHY or PRO, and no interactions (p > 0.05) were found between enzyme combinations. Substrates in experimental diets involving various enzyme combinations should be given careful consideration.

Poultry doi: 10.3390/poultry4020021

Authors: Iolanda Moretta Simona Principato Leonardo Brustenga Mario Antonello Principato

Dermanyssus gallinae, Ornithonyssus sylviarum, and Ornithonyssus bursa are ectoparasitic bird mites that affect both avian hosts and humans, causing economic losses in poultry farming and dermatological issues in humans. Due to their small size and transient feeding behaviour, mite-induced dermatitis is often misdiagnosed. In this study, over 4900 cases of entomodermatoses, recorded at the Urania Research Centre and the Department of Veterinary Medicine of Perugia—Parasitology Section between 2010–2024, were analysed, selecting cases linked to bird mites. Data on lesion onset, timing, infestation location, environmental factors, lesion type, and symptoms were examined. Avian Dermanyssoidea mites were responsible for about 4% of dermatological cases, with D. gallinae and O. sylviarum being the most prevalent, while O. bursa was less frequent. Species identification was also based on the morphology of the chelicerae and palps, with cases peaking in spring and summer. These mites were widely distributed across Italy, and Ornithonyssus species caused more severe skin reactions than Dermanyssus. Infestations often involved both genera. This study provides the first large-scale analysis of bird mite infestations in Italy, offering new insights into their distribution, infestation dynamics, and clinical symptoms. The findings contribute to improving diagnostic accuracy, pest control strategies, and public health interventions.

Poultry doi: 10.3390/poultry4020020

Authors: Suresh Neethirajan

The relentless drive to meet global demand for poultry products has pushed for rapid intensification in chicken farming, dramatically boosting efficiency and yield. Yet, these gains have exposed a host of complex welfare challenges that have prompted scientific scrutiny and ethical reflection. In this review, I critically evaluate recent innovations aimed at mitigating such concerns by drawing on advances in behavioral science and digital monitoring and insights into biological adaptations. Specifically, I focus on four interconnected themes: First, I spotlight the complexity of avian sensory perception—encompassing vision, auditory capabilities, olfaction, and tactile faculties—to underscore how lighting design, housing configurations, and enrichment strategies can better align with birds’ unique sensory worlds. Second, I explore novel tools for gauging emotional states and cognition, ranging from cognitive bias tests to developing protocols for identifying pain or distress based on facial cues. Third, I examine the transformative potential of computer vision, bioacoustics, and sensor-based technologies for the continuous, automated tracking of behavior and physiological indicators in commercial flocks. Fourth, I assess how data-driven management platforms, underpinned by precision livestock farming, can deploy real-time insights to optimize welfare on a broad scale. Recognizing that climate change and evolving production environments intensify these challenges, I also investigate how breeds resilient to extreme conditions might open new avenues for welfare-centered genetic and management approaches. While the adoption of cutting-edge techniques has shown promise, significant hurdles persist regarding validation, standardization, and commercial acceptance. I conclude that truly sustainable progress hinges on an interdisciplinary convergence of ethology, neuroscience, engineering, data analytics, and evolutionary biology—an integrative path that not only refines welfare assessment but also reimagines poultry production in ethically and scientifically robust ways.

Poultry doi: 10.3390/poultry4020019

Authors: Ana Carolina Amorim Orrico Brenda Kelly Viana Leite Juliana Dias de Oliveira Karina Fidelis Blans Isabella da Silva Menezes Vanessa Souza Régio Marcio Toesca Gimenes Rusbel Raul Aspilcueta Borquis Marco Antônio Previdelli Orrico Junior

Rearing broiler chickens generates large quantities of waste material in the form of bedding. Anaerobic digestion (AD) is a technology that can be applied to this waste. This study aimed to evaluate the AD of broiler litter, either screened (S) or unscreened (US), from different flocks, collected from each production batch, totaling nine, from a commercial farm. Anaerobic digestion was conducted in batch biodigesters, and fraction separation was performed through screening prior to loading. The S substrate from the second and fifth flocks did not produce biogas. Reductions in total (TS) and volatile solids were highest for S substrates from the third flock (50.5% and 58.3%, respectively). Only the third flock’s S substrates showed greater reductions in solids than the US substrates. Potential biogas and methane production were also highest in the third flock’s bedding for both the S substrate (336.8 and 218.2 L/kg of TS, respectively) and the US substrate (296.8 and 213.4 L/kg of TS, respectively). The methane concentration in the S substrate was highest in the third flock (64.8%), while in the US substrate, it was highest in the third and fourth flocks (70.3%). Screening the litter reduced the process efficiency. We conclude that fraction separation is inadvisable for broiler litter.

Poultry doi: 10.3390/poultry4020018

Authors: Dimitri M. Malheiros Ramon D. Malheiros Kenneth E. Anderson Peter R. Ferket

The objective of this study was to evaluate the effects of free or microencapsulated trace mineral (TM) premixes at normal and high dietary inclusion levels on the internal and external quality and mineral composition of broiler breeder eggs. Twelve breeder pens were randomly assigned to one of four treatments consisting of a factorial arrangement of two TM premix forms (free and microencapsulated) and two dietary inclusion levels of TM premix (100% and 300% of Aviagen recommendations). Hens fed the microencapsulated TM had significantly greater vitelline membrane strength than those fed the free TM (1.92 g vs. 1.81 g, respectively (p < 0.05)). Hens fed high dietary TM levels produced eggs with significantly greater shell elasticity and yolk color than hens fed the lower TM inclusion level (0.224 mm vs. 0.247 mm, and 8.89 vs. 8.62, respectively (p < 0.05)). Only the whole-egg Mn concentration was observed to be significantly (p < 0.01) increased by the higher dietary inclusion level of TM compared to lower (0.0301 mg/g vs. 0.0248 mg/g, respectively (p < 0.01)). There were no treatment effects on eggshell mineral composition. Regardless of the dietary inclusion level, feeding broiler breeders microencapsulated TM does have some beneficial effects on the internal egg quality properties, whereas increased dietary TM supplementation levels improve the shell quality, yolk color index, and whole-egg Mn concentration. There were no significant premix form X TM premix dose effects observed.

Poultry doi: 10.3390/poultry4020017

Authors: Dimitri M. Malheiros Ramon D. Malheiros Kenneth E. Anderson Peter R. Ferket

Lipid matrix microencapsulation is hypothesized to improve bioavailability for broiler breeders supplemented with normal and protect against excessive levels of inorganic trace minerals. At 27 weeks (wk), nine females and two males were assigned to each of the 12 floor pens. Each pen was randomly assigned to dietary treatments (trt) in a factorial arrangement of two mineral premix forms, free (FRTM) and microencapsulated (MITM), and two mineral premix supplement dosages (100% and 300% of Aviagen recommendations). At 55 wk termination, 15 hens/trt were randomly selected to assess tibia and jejunum morphology. Breeders receiving MITM improved hen day % (HD %), hen housed (HH%), and FCR but produced the lightest chicks at hatch. The TM form had no significant effect on histology, but TM 100% had greater villus height (VH), crypt depth (CD), and villi area than TM 300% (p < 0.5). No significant treatment effects on bone weight, length, and bone mass density were observed. However, MITM treatments increased tibia thickness, and FRTM supplementation increased ash% and Cu content. Hens fed 300% TM had higher bone Mn content than 100% TM, whereas hens fed MI100 had the highest Fe content. Feeding lipid matrix microencapsulated trace minerals to broiler breeders does have positive impacts on the production of eggs, but no effects were observed in the histomorphology of the jejunum or tibia bone parameters.

Poultry doi: 10.3390/poultry4020016

Authors: Miguel Matos Ivana Bilic László Kőrösi Rakibul Hasan Dieter Liebhart Nicola Palmieri Michael Hess

This study reports an outbreak of hepatitis-splenomegaly syndrome (HSS) in a color broiler parent stock flock in Bangladesh, marking the first known instance of HSS associated with avian hepatitis E virus (aHEV) genotype 7 outside Europe and only the second report of HSS in South Asia. The affected flock exhibited severe clinical signs, including a high cumulative mortality, reaching 31.6% in hens, and an abrupt decrease in egg production, dropping by over 20 percent. Histopathological analysis of liver and spleen samples revealed multifocal areas of necrosis, hemorrhages, and bacterial colonies. RT-PCR confirmed the presence of aHEV and immunohistochemistry showed signals within hepatic sinusoids and peri-ellipsoidal zones in the spleen. Complete genome sequencing of RNA from liver and bile samples on the Illumina platform established a pathogenic link to aHEV genotype 7. Despite aHEV’s known association with HSS, inconsistencies in disease manifestation suggest additional cofactors influencing pathogenesis, with secondary bacterial infections potentially contributing to clinical severity in this outbreak. Overall, this case expands the geographic distribution of aHEV genotype 7 and highlights the need for further epidemiological studies to investigate genotype–pathogenicity associations, especially in regions with limited prior data on HSS.

Poultry doi: 10.3390/poultry4020015

Authors: Mitchell C. Rowland Kyle D. Teague Aaron J. Forga James Higuita Makenly E. Coles Billy M. Hargis Christine N. Vuong Danielle Graham

Probiotics have been used to promote pioneer colonization by beneficial bacteria in poultry. The purpose of the present study (four trials) was to determine if an in ovo injection with Bifidobacterium saeculare (B2-2, B3-4) and/or lactic acid bacteria (LAB18, LAB46) at d18 of embryogenesis reduced Enterococcus and Gram-negative bacterial colonization in the gut at hatch. An environmental challenge model was used to simulate microbial contamination in large-scale hatch cabinets in a laboratory setting. In all trials, gut homogenates obtained from chicks at hatch were plated to enumerate relevant bacterial populations. Performance was evaluated in trials two and four. The top treatments in trial one were selected for further testing in trials 2–4. The significance level for all analyses was set at p < 0.05. A meta-analysis of gut bacterial recovery for trials 2–4 revealed that the administration of probiotic treatments increased LAB and/or bifidobacteria at hatch compared to non-treated groups. LAB46 + B2-2 was more effective at reducing Gram-negative bacteria and Enterococcus in the gut compared to other probiotic treatments. All treatments improved d14 BW and d0–14 BWG compared to non-treated groups. These results indicate that exposure to beneficial bacteria during late embryogenesis can prevent colonization by opportunistic pathogens associated with contamination in commercial hatch cabinets and may also improve early performance in broiler chickens.

Poultry doi: 10.3390/poultry4010014

Authors: Deborah Olubanjo Artur Zbikowski Bishnu Adhikari Tieshan Jiang Pallavi Singh Seong W. Kang Young Min Kwon

The presence and biological role of extracellular DNA (eDNA) have been explored in diverse microbial environments. Nonetheless, it has not been studied in the chicken gut microbiome. This study aims to investigate eDNA in the chicken cecum, analyzing cecal samples from broiler chickens using three preparation methods: Whole Cecal Suspension (WCS), Washed Cell Pellets (WCP), and Cell-Free Supernatant (CFS). The 16S rRNA gene-based microbiota analysis revealed distinct microbial communities in CFS compared to WCS and WCP (p = 0.001). Notably, specific taxa, including Anaerofilum, Anaerotruncus, Oscillospira, Syntrophomonas, and Delftia, were enriched in CFS. Confocal fluorescence microscopy, employing stains such as Propidium Iodide (PI), GelGreen, and SYTO 9, confirmed the presence of eDNA with filaments observed in WCS and CFS. Colocalization of PI and GelGreen™ validated the extracellular nature of eDNA, while DNase I treatment selectively degraded eDNA, further confirming its extracellular nature. Our findings in this study highlight the presence of eDNA in the chicken cecal microbiome, and the presence of eDNA associated with specific taxonomic groups suggest that it might play a specific role in the biological function of the cecal microbiome, which warrants further investigation in the future.

Poultry doi: 10.3390/poultry4010013

Authors: Sousan Khanipour Mahmoud Ghazaghi Mohammad Reza Abdollahi Mehran Mehri

There was an error in the original publication [...]

Poultry doi: 10.3390/poultry4010012

Authors: Md Safiul Alam Bhuiyan Gilbert Ringgit Subir Sarker Ag Muhammad Sagaf Abu Bakar Suryani Saallah Zarina Amin Sharifudin Md. Shaarani Shafiquzzaman Siddiquee

Infectious bronchitis virus (IBV) is an enveloped, positive-sense, single-stranded RNA virus belonging to the genus Gammacoronavirus. It primarily infects avian species, causing respiratory and renal disease and irreversible damage to the oviduct, which can lead to high mortality rates in chickens. The lack of rapid and reliable diagnostic tools for on-farm IBV detection hampers timely disease management and control measures. The introduction of DNA biosensors offers a promising approach for the sensitive and specific detection of IBV, facilitating rapid identification and intervention. In this study, an electrochemical DNA biosensor with a multi-walled carbon nanotube (MWCNT)-modified gold electrode was developed for IBV detection. The biosensor targeted the target-specific 5′ untranslated region (5′-UTR) of the IBV genome. Under optimal conditions, the immobilization and hybridization efficiencies were evaluated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV), with methylene blue as a redox indicator. The developed DNA biosensor demonstrated a dynamic detection range from 2.0 × 10−12 to 2.0 × 10−5 mol L−1, with a limit of detection (LOD) of 2.6 nM and a limit of quantification (LOQ) of 0.79 nM. Validation using a small subset of clinical samples, including crude complementary DNA, and polymerase chain reaction products, showed high recovery rates ranging from 95.41% to 99.55%. While these findings highlight the potential of the proposed DNA biosensor as an innovative diagnostic tool for IBV detection, this study remains a proof of concept. However, further validation using a large number of clinical samples is essential to assess its feasibility, robustness, and practical application in a real-world farm setting

Poultry doi: 10.3390/poultry4010011

Authors: Donald L. Reynolds E. Barry Simpson Matthew M. Hille

Enterococcus faecalis (E. faecalis) is a ubiquitous microbe occurring in the environment and in the intestinal tract of poultry. E. faecalis has been identified in cases of egg infertility and/or decreased hatchability and can cause amyloid arthropathy in older laying chickens. E. faecalis produces cytolysin, a bacterial exotoxin that can cause lysis of erythrocytes. It has been difficult to demonstrate this virulence trait using conventional culture methods with sheep blood agar. A 96-well microplate hemolysis assay, along with a culture method incorporating glucose and L-arginine into the culture media, is described that demonstrates the production of cytolysin in E. faecalis isolates of avian origin. Additionally, the results show that horse and sheep erythrocytes were susceptible to lysis by the E. faecalis cytolysin, but cow and chicken erythrocytes were less susceptible.

Poultry doi: 10.3390/poultry4010010

Authors: Caio Júnior Lúcio Paulo Henrique Caminha Hansen Josiane Griebeler Diéssy Kipper Vagner Ricardo Lunge

Colibacillosis is a chicken disease caused by avian pathogenic Escherichia coli (APEC). Pathogenicity in birds is determined by the occurrence of bacterial genes encoding virulence factors in APEC strains. Furthermore, APEC and other bacterial infections in commercial poultry farms have been treated with intensive use of antimicrobials for decades. Currently, many APEC strains are no longer susceptible to frequently used antibiotics due to increasing antimicrobial resistance (AMR) associated with the acquisition and mutation of other specific bacterial genes. The present study aimed to isolate and detect APEC isolates in broiler farms from different poultry-producing regions of Brazil and to determine their AMR profile. A total of 126 E. coli isolates were obtained from necropsied chickens with colibacillosis. All of these E. coli isolates were analyzed with one species-specific qPCR (targeting uspA gene) and five virulence factors genes qPCRs (targeting iroN, hlyF, iutA, iss, and ompT). AMR was determined by disk diffusion method using ten drugs frequently used to treat colibacillosis in Brazilian poultry farms. The results demonstrated that 109 (86.5%) isolates were classified as APEC. AMR was commonly observed in APEC and AFEC isolates, highlighting resistance for amoxicillin (85; 67.4%) and ceftiofur (72; 57.1%). A total of 41 (32.5%) E. coli isolates presented a multidrug resistance (MDR) profile. These results can contribute to implementing more effective colibacillosis prevention and control programs on Brazilian poultry farms.

Poultry doi: 10.3390/poultry4010009

Authors: Aleksandra Atanasova Thomas Amon Anika Friese Uwe Rösler Roswitha Merle Christiane Herrmann Anton Kraus Tina Kabelitz

Anaerobic digestion (AD) is a suitable process to use manure for biogas production. During this process, antimicrobial resistant (AMR) bacteria are reduced. In this study, we investigated the reduction of extended-spectrum beta-lactamase (ESBL)-producing, fluoroquinolone-resistant, and total Escherichia (E.) coli concentrations in chicken manure during AD. AD was performed at 30 °C and 37 °C (mesophilic temperature range), with and without sawdust addition as a lignocellulosic biomass. The initial concentrations of total E. coli were 6.43 log10CFU/g to 7.84 log10CFU/g. The concentration of Fluoroquinolone-resistant E. coli was approx. 6.05 log10CFU/g (6.70%), and of ESBL-producing E. coli approx. 5.48 log10CFU/g (0.99%). During AD, we observed that temperature had the main influence on the bacterial reduction, as E. coli abundance was below the detection limit after day 7 at 37 °C and after day 14 at 30 °C. At 37 °C we observed higher amounts of free ammonia, which is an inhibitor of the AD process. The carbon-to-nitrogen (C/N) ratio has an important impact on the AD process because a higher C/N ratio decreases the amount of generated total ammonia nitrogen. However, we did not observe a significant difference in AMR and total E. coli reduction between chicken manure with a natural C/N ratio (10:1) and an increased C/N ratio (25:1).

Poultry doi: 10.3390/poultry4010008

Authors: Amanda Rosenbaum Silke Rautenschlein Arne Jung

Knowledge about chickens’ immune response to infection with Enterococcus cecorum (EC) and prophylactic strategies is scarce. This study aimed to investigate the protective effect of an EC-specific hyperimmune serum after experimental challenge with homologous EC. A total of 284 one-day-old meat-type chickens were randomly assigned to three groups (non-inoculated (C), passively immunized with hyperimmune serum and EC-inoculated (EPI), and EC-inoculated (E)). At 1 and 2 days post-hatch (dph), the hyperimmune serum was subcutaneously administered to each chicken in group EPI. Oral inoculation with EC was carried out at 2 dph. Blood samples and cloacal swabs were collected at 7, 14, 21, 28, and 35 dph and necropsy was carried out at 42/43 dph. Extraintestinal colonization with EC was significantly decreased in group EPI compared to group E. Additionally, femoral head necrosis and spondylitis of the free thoracic vertebra were significantly decreased in group EPI compared to group E. Flow cytometric analysis revealed a significant increase in heterophils, monocytes, and the heterophil/lymphocyte ratio in the peripheral blood of bacteriological positive chickens. Although the parenteral application of a hyperimmune serum lacks practicability in meat-type chicken flocks, the results of this study encourage further research on vaccination of meat-type chicken breeder flocks.

Poultry doi: 10.3390/poultry4010007

Authors: Louise Hedlund Dominic Wright Per Jensen

A social network is a group of individuals forming a non-random social structure where the number of interactions systematically vary among individuals. The Red Junglefowl, the ancestor of all domesticated chickens, has been shown to form social structures within a larger group; however, how poultry in egg production are socially organised is poorly understood. Egg layers in groups of thousands of individuals are suggested to either, just as Red Junglefowl, form subgroups or to lose social affiliations and replace these with a system of social tolerance. In this case study, a stable group of 20 laying hens with known genetic relationships housed in an outdoor aviary were observed for 3 h per day, during 20 days, in order to determine the social structure in the group. Social affiliations and centralisation measurements were assessed by proximity. The results show that some individuals were consistently more centralised compared to others, which indicates a stable individual variation in sociality. Furthermore, no individual spent more than 10% of her total number of interactions with a particular individual, i.e., little consistency in social affiliations could be found. The results of this case study support the theory of a higher social tolerance rather than a consistent social organisation in domesticated egg layers.

Poultry doi: 10.3390/poultry4010006

Authors: Leilane R. B. Dourado Adriana S. A. Brauna Roseane M. Bezerra Iara S. Sousa Franscica Luana A. Carvalho Gabriela G. Silva Francinete A. S. Moura Samara C. Sousa Renato A. Santos Silvokleio C. Silva Lucilene S. Silva Larissa Maria F. Gonçalves Rafael S. Miranda

This experiment evaluated the effects of including buriti oil (BO) in the diet of broilers on growth performance, nutrient digestibility, carcass yield, meat quality, blood parameters, intestinal morphometry, the proliferation of collagen fibers in the skin and collagen concentration in the breast muscle. A total of 180 one-day-old Ross male chicks were distributed in a completely randomized experimental design with three treatments (0%, 1% and 2% BO) and six replications of 10 birds each. Nutrient digestibility was evaluated from 8 to 21 days, while the performance, carcass yield, meat cut yields, abdominal fat, meat quality, blood parameters, intestinal morphometry and skin histology of the birds were evaluated after 21 days. The inclusion of BO significantly affected (p ≤ 0.05) performance, digestibility, meat color, lymphocyte count, duodenal morphometry and collagen concentration. In addition, it increased the metabolizable energy of the diet and reduced the birds’ performance, indicating that the nutraceutical effect of BO improved nutrient use. However, it caused an excess of energy that had to be metabolized by the birds, consequently affecting their performance. BO increased the pigmentation of the breast meat and reduced the lymphocyte count, probably due to its antimicrobial action, consequently decreasing the recruitment of defense cells. An increase in the height of the crypt of the duodenum was observed as the inclusion of BO increased, with the opposite being observed in the jejunum. The inclusion of BO increased the histological proliferation of collagen from minimal (0%) to medium (1%) and moderate (2%), as well as the collagen concentration (CC = 35.933 + 4.677BO; R2 = 0.80). Thus, due to functional/nutraceutical effects, adding BO in the diet of broilers can be a promising alternative to antibiotic growth promoters to improve poultry production.

Poultry doi: 10.3390/poultry4010005

Authors: Lethícia Olimpio Bueno Dalila Lima Dinali Alcinéia de Lemos Souza Ramos Eduardo Mendes Ramos

The growth in quail egg production presents opportunities to utilize spent laying quail meat in value-added products, thereby enhancing the poultry industry. This study aimed to develop and evaluate sausages made with quail breast meat (QBM), chicken breast meat (CBM), mechanically deboned quail meat (MDQM), and mechanically deboned chicken meat (MDCM). The poultry breast and deboned meat samples were characterized and used to prepare five sausages (S1 = 100% CBM, S2 = 100% QBM, S3 = 60% CBM + 40% MDQM, S4 = 60% QBM + 40% MDCM, and S5 = 50% MDCM + 50% MDQM). QBM exhibited a higher protein content (25.26%) than CBM (22.33%), while MDQM contained higher collagen (1.23%) and ash (3.78%) contents than that of MDCM. MDCM displayed a darker (lower L*), redder (lower h), and more intense (higher C*) color than MDQM. Sausages containing mechanically deboned poultry meat (S3, S4, and S5) exhibited a more yellowish (h = 62.9°) tone compared to those containing only breast meat (h = 56.2°). S4 sausages exhibited the highest sensory acceptability (score 7.2), whereas S5 sausages, described as having a dark, non-uniform appearance and sandy texture, were less preferred (score 5.1). These findings highlight the potential of spent quail meat in sausage production, offering a promising avenue for product innovation and market expansion.

Poultry doi: 10.3390/poultry4010004

Authors: Dimitrios Galamatis Ioannis Panitsidis Tilemachos Mantzios Georgios Sioutas Ioanna Stylianaki Elias Papadopoulos Jog Raj Marko Vasiljević Jasna Bošnjak-Neumüller Damer Blake Vasilios Tsiouris Ilias Giannenas

This study evaluated the effectiveness of phytobiotic supplementation in managing coccidiosis in broiler chickens, a disease that impacts productivity. Three hundred sixty Ross-308 one-day-old chicks were assigned to five treatment groups: control negative (CN), phyto negative (PN), control infected (CI), phyto infected (PI), and salinomycin infected (SI). All diets were fed for the entire experiment duration. CN and CI groups were given a common diet, with CN remaining uninfected and CI exposed to Eimeria spp., while PN and PI groups received a phytobiotic supplement containing essential oils, saponins, and tannins (with PI challenged by Eimeria spp.), and SI received salinomycin post-infection. All infected groups were challenged on day 14 with Eimeria acervulina, E. maxima, and E. tenella. By day 21, PN had the highest body weight (744.9 g). Body weight gain (BWG) was highest in CN and PN from days 14–35, while CI consistently showed the lowest BWG. PI demonstrated significantly lower oocyst counts than CI, outperforming even SI by day 7, and showed milder intestinal lesions. A high anticoccidial index (ACI) of 188.45 was observed in PI, close to uninfected groups, while SI achieved a partially effective ACI of 136.91. Overall, PN and PI exhibited improved performance and intestinal health, highlighting the potential of phytobiotics in coccidiosis management for broilers.

Poultry doi: 10.3390/poultry4010003

Authors: Amine Mernizi Abdeljelil Ghram Hicham Fathi Enrique Carceller Juan-Luis Criado Martina Dardi Oumayma Arbani Mohammed Bouslikhane Mohammed Mouahid Caterina Lupini Elena Catelli Siham Fellahi Saadia Nassik

Avian Metapneumovirus (aMPV) is a significant poultry pathogen with a global presence, primarily causing respiratory issues in turkeys. It also affects chickens, although the severity of its impact is often lessened in this species. In Morocco, aMPV has been detected in broiler flocks, prompting the need to deeply analyze circulating strains to better understand the epidemiology and develop control measures accordingly. This research focuses on the sequencing and molecular characterization of aMPV in these flocks. Additionally, aMPV isolated from turkeys displaying Turkey Rhinotracheitis (TRT) signs was included in the study to compare the findings. RNA extracted from positive swabs was subjected to nested PCR, targeting the attachment protein of the G gene, followed by gel electrophoresis. Amplicons were purified and sequenced using the Sanger method. Bioinformatics tools facilitated sequence analyses, including BLAST for similarity searches and Mega® for phylogenetic analysis using the maximum likelihood method with 1000 bootstrap replicates. The investigation unveiled the existence of two distinct clades of the aMPV/B isolates, which originated from used vaccines, all circulating in broilers and turkeys and indicating potential virus transmission between both poultry species. This article presents the first-ever molecular characterization of aMPV isolated from Moroccan broilers and turkeys, encompassing comprehensive investigations on its presence and subtype, and genetic characterization.

Poultry doi: 10.3390/poultry4010002

Authors: Jose I. Vargas Abigail D. McConnell Joseph P. Gulizia Wilmer J. Pacheco Kevin M. Downs

Chickens possess a well-developed vision that allows them to perceive a wide range of the color spectrum. In addition, they display an inherent sensitivity toward specific light spectra, which suggests that coloring feed could influence feed preference, feed intake and growth performance. This trial assessed the effect of feed coloring on broiler feed color preferences. A total of 216 day-old Cobb by-product males were randomly distributed into 18 battery cages, each containing 12 chicks and subjected to three dietary treatments from 1 to 21 days, resulting in six replicates per dietary treatment. Feed color treatments consisted of a common corn–soybean meal-based undyed basal (UB) broiler starter diet, which was dyed to obtain blue-colored (B) and purple-colored (P) diets, resulting in a total of three diets used to create the feed combinations. Two feed troughs were affixed to each cage, allowing for the assignment of dietary treatments as follows: UB-B, UB-P, and B-P. The birds had ad libitum access to feed and water throughout the study. Feed consumption data were collected at 7-day intervals. Additionally, bird weights were measured at 1 and 21 days. The data were analyzed as a completely randomized design using the SAS GLIMMIX and TTEST procedures. Overall, broilers exhibited a preference for the UB diet compared to the B and P diets. Broilers had a 27.5 and 29.2% higher (p < 0.05) feed consumption of UB feed compared to P feed from 1 to 14 and 1 to 21 days, respectively. In addition, broilers tended to have a higher (p = 0.098) consumption of UB feed compared to B feed from 1 to 14 days. No differences were observed in feed consumption between B and P diets during the experimental period. Based on feed consumption data, broilers displayed a preference towards the UB feed when paired with B or P diets. Feed coloring did not impact the mortality of broilers and did not result in adverse growth. Overall, broilers preferred the UB diet over the B and P diets and showed no preference between B and P diets. Based on the results of this trial, diets that appear more conventional, compared to dyed diets, can promote consumption. Special care must be taken to avoid ingredients that could alter the diet’s coloration.

Poultry doi: 10.3390/poultry4010001

Authors: Praise Jegede Abdulmojeed Yakubu Ibrahim S. Musa Samuel T. Vincent Ayoola J. Shoyombo Olayinka O. Alabi Mathew Wheto Ayotunde O. Adebambo Mustapha A. Popoola

This study was conducted to compare the fertility and hatchability performance of the Nigerian indigenous and exotic helmeted guinea fowls and predict egg weight from egg indices in Nigeria. A total of 300 randomly selected 8-month-old guinea fowls, comprising 150 indigenous (30 males and 120 females) and 150 exotic birds (30 males and 120 females), were utilized in this study. Consequently, a total of 240 randomly selected eggs (120 per genotype) were used separately for the reproductive and egg quality assessments. The fertility and hatchability parameters were subjected to descriptive statistics (numbers and percentages), while the 17 egg quality parameters were analyzed using a T-test, phenotypic correlation, principal component analysis, multiple linear regression, and a CHAID decision tree. Percentages of fertility (90.0 and 73.3%) and hatchability (66.7 and 56.8%) were higher in the exotic birds compared to their indigenous counterparts. The egg quality parameters of the exotic birds were higher (p < 0.05) than those of the indigenous birds, with the exception of egg shell index (18.88 ± 0.79 versus 16.41 ± 0.69) and Haugh unit (92.37 ± 3.13 versus 91.09 ± 3.22). However, the mean yolk/albumen ratio was similar (p > 0.05). The phenotypic correlation coefficients between egg weight and egg quality indices in both genetic groups ranged from low to high values [−0.05–0.95 (indigenous); −0.19–0.96 (exotic birds)]. Three principal components sufficiently accounted for the variations in the egg quality traits of both genetic groups. The CHAID algorithm was more consistent in egg weight prediction, with egg width as the primary explanatory variable. The present information may guide breeding and management strategies geared towards the improvement of the reproductive and egg quality traits of the helmeted guinea fowls.

Poultry doi: 10.3390/poultry3040034

Authors: Indibabale Kumalo Victor Mlambo Caven Mguvane Mnisi

We evaluated the effect of replacing maize with graded levels of banana (Musa acuminata) peels (BPs) on feed utilisation, physiological performance, and meat quality traits in Jumbo quail. In a completely randomised design, 341 one-week-old, unsexed quail chicks were randomly allocated to 30 cages and reared on five experimental diets containing 0 (BP0), 25 (BP25), 50 (BP50), 75 (BP75), and 100 g/kg BP (BP100) in a conventional grower diet. Dry matter, organic matter, and gross energy digestibility values linearly declined (p < 0.05) with BP levels. Feed intake in the 5th week linearly declined (p < 0.05) as BP levels increased. The BP0 diet promoted greater overall body weight gain than BP100. Similarly, birds on BP0 had a higher (p < 0.05) overall gain-to-feed ratio than birds on BP75 and BP100. Significant linear increases were observed for relative gizzard, and small and large intestine weights. There were negative quadratic effects (p < 0.05) for relative proventriculus weight, breast lightness, and thigh chroma as BP levels increased. Furthermore, thigh yellowness linearly decreased, while hue angle linearly increased with BP levels. The partial substitution of maize with BP in Jumbo quail diet compromised feed digestibility and performance parameters, stimulated visceral organ development, and altered some meat colour attributes.

Poultry doi: 10.3390/poultry3040033

Authors: Carlos Daniel Gornatti-Churria Sebastián Brambillasca Patricio A. García

Melanosis is scarcely reported as a potential cause of carcass downgrading in broilers worldwide. We described the preliminary diagnostic findings of dermal and celomic fat tissue melanosis in a total of four episodes of increased downgrading in 31-to-50-day-old male Cobb500TM broiler chicken carcasses at a processing plant in Argentina from November 2016 to March 2022. Veterinary inspectors evaluated and sampled a total of 10 carcasses. Gross findings included the gray discoloration of subcutaneous tissue in wings and legs, celomic fat tissue and peritoneum. Microscopically, melanocytes infiltrated the connective tissue and adipose cells of subcutaneous tissue in the skin of legs and wings as well as the celomic fat tissue of all 10 birds. The Fontana–Masson stain revealed black melanin granules in subcutaneous tissue and celomic fat tissue, demonstrating its value as a histologic tool to confirm grossly compatible melanosis in all of the evaluated tissues sampled at the broiler processing plant. We propose to add melanosis as one of the less frequently and rare diagnosed cutaneous darkening conditions which potentially contributes to downgrading in chicken processing plants globally.

Poultry doi: 10.3390/poultry3040032

Authors: Ismail A. Raheel Ahmed R. Elbestawy Mohamed S. Diab Mervat A. Abdel-Latif Nehal Tag Ahmed Orabi

The development of effective and innovative vaccination strategies is urgently needed to better control the spread and transmission of the low-pathogenic avian influenza H9N2 subtype (LPAI-H9N2) in poultry. In addition, the enhancement of innate immunity by some of these innovative inactivated vaccines has not yet been investigated. Here, an experiment was conducted in commercial broiler chickens to compare the immune response to two different inactivated H9N2 vaccines. For this, Group 1 (G1) broilers were vaccinated with vaccine 1 [Nobilis® H9N2-P (pathogen-associated molecular patterns—PAMP) technology], broilers in G2 were vaccinated with vaccine 2 [an inactivated whole H9N2 virus (IWV) autogenous oil emulsion vaccine], while birds in G3 were not vaccinated. The study lasted 34 days. Innate immune parameters (phagocytic activity, nitric oxide, and lysozyme), cytokine signaling (IL-1β, IL-6, IL-8), humoral immunity using the hemagglutination inhibition (HI) test, and the gene expressions of IFN-γ and TLR-21 were assessed. The results showed a significant increase in innate immunity and modulatory cytokines at 24–48 h after the vaccination of G1 broilers, with a continuous increase until the end of the experiment. In addition, a significant increase in geometric mean HI titers was observed in G1 at 11 days post-vaccination (dpv), and a significant (p ˂ 0.05) upregulation of IFN-γ and TLR-21 was observed in the same group, G1, at 31 dpv compared to G2 and G3. Nobilis® H9N2-P may induce faster and stronger innate and active humoral immunity compared to another IWV, which may contribute to the protection of broilers against early H9N2 infections. However, challenge protection studies for several IWV vaccines, including PAMP-H9N2 against LPAI-H9N2, should be further evaluated in both specific pathogen-free (SPF) and commercial broilers.

Poultry doi: 10.3390/poultry3040031

Authors: Dayse Helena Lages da Silva Luana Ferreira Marques Cordeiro Diego Lisboa Rios Oliveiro Caetano de Freitas Neto Leonardo José Camargos Lara Juan Carlos Ariute Oliveira Flávia Figueira Aburjaile Roselene Ecco

Gizzard erosion and ulceration (GEU) is characterized by defects and necrosis in the koilin layer, particularly in broilers. This condition has been associated with growth retardation, runting, and economic implications for poultry producers; nevertheless, its influence on gut microbiota remains unknown. This study investigated the compositional changes in the bacterial community of the ileum of seven-day-old broiler chicks with GEU using next-generation sequencing (NGS) technology. Twenty-two samples were obtained from the ileal mucosa and contents of sixteen chicks with GEU and six without GEU raised in a conventional system located on a farm in southeast Brazil. The results revealed that bacterial phyla in both groups exhibited a similar composition, with Firmicutes representing the most abundant. Porphyromonas, Candidatus Arthromitus, and Limosilactobacillus were statistically more abundant in the group without GEU. The most prevalent genera in the group with GEU were Lactobacillus and Enterococcus, and the relative abundance of Enterococcus in the ilea of some chicks with GEU was considerable. Based on the results of the current study, necrosis in the koilin layer can change the composition of ileal microbiota. Therefore, further studies should be carried out to clarify whether GEU and consequently poor digestibility of the feed cause significant changes in the intestinal microbiota.

Poultry doi: 10.3390/poultry3040030

Authors: Thanh Tien Tran Nicholas Andronicos Priscilla F. Gerber

Changes in leukocyte populations and immune gene expression associated with attenuated vaccine (SA2) or field (Class 9) strains of infectious laryngotracheitis virus in chicken pullets were observed primarily in the trachea and conjunctiva, while no substantial changes were detected in the Harderian gland. Although there were no significant differences in cellular infiltration in the tissues exposed to Class 9 and SA2, Class 9 induced greater changes in immune gene expression than SA2 in the trachea and conjunctiva and significantly upregulated CD4, CD8A, IRF1, STAT4 and downregulated CXCL12 expression in the trachea. Meanwhile, SA2 significantly upregulated CD14 and downregulated MPO, CCR6 and RAG1 expression in the conjunctiva. In conclusion, gene expression in pullets infected with SA2 and Class 9 were mostly related to inflammatory and tissue-repairing responses in the trachea and conjunctiva. Compared to SA2, Class 9 inoculation was associated with a more robust gene expression of immune markers; however, a larger infiltration of Kul01+, Bu1+ and CD8a+ cells was observed in trachea and conjunctiva after SA2 inoculation.

Poultry doi: 10.3390/poultry3040029

Authors: Christopher Manchishi Kanyama Mathews Ngosa Terence Z. Sibanda Amy F. Moss Tamsyn M. Crowley

(a) Introduction: Zambia’s poultry industry comprises commercial chickens and small-scale producers of indigenous chickens (Gallus domesticus) (ICs). Large, integrated entities run the commercial chicken sector, while the indigenous chicken sector (IC sector) is predominantly run by small-scale farmers (SSFs). Increased costs and low access to formal markets for commercial chickens have motivated SSFs to enter the IC sector under the free-range system (FRS) and semi-intensive system (SIS). (b) Objective: This study aimed to highlight the price changes in poultry inputs and outputs and demonstrate that the IC sector has more potential to contribute to farm income than commercial chickens under family poultry production systems. (c) Method: We analysed the prices for inputs and outputs for Zambia’s poultry industry for the first quarter of 2016 to 2023 using data from the Poultry Association of Zambia (PAZ). We also analysed data from the 2021 Qualtrics survey to investigate the crops grown and crops used as feed and feed ingredients, the sources of feed, and the use of minerals and vitamins by SSFs for chickens. The gross profit (GP) and benefit–cost ratio (BCR) were analysed to compare the viability and profitability of ICs and broilers under SSFs. (d) Results: Our study shows that prices for day-old chicks (DOCs) and point-of-lay (POL) pullets increased by 57–125%, broiler and layer feeds increased by 67–96%, and soybean meal (SBM) and fishmeal rose by 143–229%. Prices for live ICs, commercial broilers, and ex-layers increased by 150%, 79%, and 71%, respectively. Egg prices rose by 100–124%. Farmers tried to look for local feed sources. Over 21% of the crops grown was maize, and nearly 43% was used for feed. (e) Conclusion: Our analysis and comparison between the ICs and broilers demonstrated that SSFs could achieve more farm income by producing ICs than commercial broilers.

Poultry doi: 10.3390/poultry3040028

Authors: Alexis J. Clark Cerano Harrison Ari J. Bragg Gabrielle M. House Aaron B. Stephan Mireille Arguelles-Ramos Ahmed Ali

Laying hens usually have 16 h of light and 8 h of darkness during egg laying, with eggshell formation primarily occurring during darkness when dietary calcium is lacking, leading to bone calcium resorption and osteoporosis. This study examined how interrupting the dark phase affects bone health in 396 Hy-line W36 hens assigned to control (C) or treatment groups (W1 and W2). All hens received 16 h of light and 8 h of darkness daily in different variations of scotophase interruption. Blood samples were taken at weeks 20, 30, 50, and 70, serum calcium was measured during darkness at two timepoints (SRT and END), and bone demineralization markers were examined using enzyme concentrations (TRACP-5b and CTX-I). Across weeks, tibias were CT-scanned for density (mg/cm3) and area (mm2), then used for breakage strength analysis (N) and ash%. No SRT Ca level differences emerged, but C hens had lower END Ca levels compared to W1 and W2 hens across all weeks, while W1 and W2 hens showed no significant differences. C hens displayed higher TRACP-5b and CTX-I concentrations across all weeks compared to W1 and W2 (all p ≤ 0.05). At week 70, C hens had the lowest cortical bone cross-sectional area and mineral density compared to W1 and W2 (all p ≤ 0.05). Tibiotarsi bone breakage strength was lower in C hens compared to W1 and W2. C hens had significantly lower ash% than treatment birds. Interrupting the scotophase period improved overall bone health in Hy-line W36 laying hens.

Poultry doi: 10.3390/poultry3040027

Authors: Amy F. Moss Rebel Northey Sukirno Aamir Nawab Nasima Akter Peta S. Taylor Hiep Thi Dao

Currently, there are no guidelines on housing or recommendations for practical environmental enrichments for chickens used for research and teaching purposes. This study was conducted to identify optimal enrichment programs to improve the health and welfare of caged hens used for teaching and research purposes. The 24-week-old Hy-line Brown laying hens (n = 168) were allocated at random to six enrichment programs/treatments with 14 replicate cages of two birds per cage during a 5-week experiment. Hens had physical access to the following treatments: no enrichment provided (control); round, wooden perches provided (perch); scratch pads made of wood and covered with sandpaper provided (scratch pad); hanging CDs provided (hanging CD); all three enrichment forms provided (complex environment); and each enrichment form provided on a 2-week rotation (novelty). While the egg quality was consistent, the complex group had a significantly lower feed intake (p < 0.001) but similar egg mass; thus, they also had a lower feed conversion ratio (p < 0.001). Additionally, hens in the complex treatment group had the leanest average body weight at week 5 (p < 0.01). It should be noted that while some measures of welfare did show significant differences, the biological or practical difference may be negligible, as in the case of the body condition score in this study. The results show that providing three different forms of environmental enrichment had positive effects on the welfare, health condition, and laying performance of laying hens relative to no enrichment or only one enrichment item.

Poultry doi: 10.3390/poultry3040026

Authors: Candice E. C. Blue Mallory B. White Rami A. Dalloul

Subclinical necrotic enteritis (NE) is an enteric disease that inflicts significant economic losses in the poultry industry, primarily by reducing performance in commercial flocks but without significant mortality. This study evaluated the effects of a variety of phytogenic blends on broilers’ performance and carcass composition during an induced NE challenge. In this study, 1120 day (d)-old male broilers were allocated to four treatments groups (14 replicate floor pens, 20 birds/pen): the control (CONT) group, fed a basal corn-soybean diet, and three phytogenic blend dietary additives (PHYTO1, PHYTO2, and PHYTO3) added to the basal diet at 150, 250, and 500 mg/kg feed, respectively. Subclinical NE was induced by spraying a concentrated coccidiosis vaccine onto the feed and litter 24 h post-placement. On day 8, two birds/pen were necropsied for NE lesions. On days 8, 14, 28, and 42, the average daily gain (ADG), feed intake (ADFI), and feed conversion ratio (FCR) were calculated. On day 42, two birds/pen were euthanized to assess carcass composition using dual-energy X-ray absorptiometry (DXA). Statistical analyses for all data were performed using the ANOVA procedure (JMP, Pro 16) and significance (p ≤ 0.05) between treatments was determined by the LSD test. There was no effect of treatment on NE lesions. PHYTO1, PHYTO2, and PHYTO3 significantly improved FCR from days 9 to 14, 0 to 14, and 0 to 42 and resulted in greater ADG from days 9 to 14, 29 to 42 and cumulatively on days 0 to 42. Carcass composition data revealed a numerically higher lean-to-fat ratio in the PHYTO groups compared to the CONT group. These results indicate that the dietary supplementation of phytogenic blends could alleviate the adverse effects of NE challenge on broilers’ performance and carcass composition.