Poultry

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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 Full article

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. Full article

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. Full article

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). Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article