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The Expression of Social Behaviors in Broiler Chickens Grown in Either Conventional or Environmentally Modified Houses During the Summer Season
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Automatic Detection of Foraging Hens in a Cage-Free Environment with Computer Vision Technology
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Assessment of Pupillometry Across Different Commercial Systems of Laying Hens to Validate Its Potential as an Objective Indicator of Welfare
Journal Description
Poultry
Poultry
is an international, peer-reviewed, open access journal on poultry health, welfare and productivity, published quarterly online by MDPI.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- High Visibility: indexed within ESCI (Web of Science), Scopus, EBSCO, and other databases.
- Journal Rank: JCR - Q2 (Agriculture, Dairy and Animal Science) / CiteScore - Q2 (Veterinary (miscellaneous))
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 34 days after submission; acceptance to publication is undertaken in 10.7 days (median values for papers published in this journal in the first half of 2025).
- Recognition of Reviewers: APC discount vouchers, optional signed peer review, and reviewer names published annually in the journal.
- Poultry is a companion journal of Agriculture.
Impact Factor:
2.1 (2024);
5-Year Impact Factor:
2.1 (2024)
Latest Articles
Black Cumin (Nigella sativa) as a Healthy Feed Additive for Broiler Production: A Focused Review
Poultry 2025, 4(4), 49; https://doi.org/10.3390/poultry4040049 - 10 Oct 2025
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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
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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.
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Open AccessReview
Relationship Between Animal Welfare Metrics, Production, Slaughter, and Economic Gain in Poultry Farming
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Deivid Kelly Barbosa, Vivian A. R. C. Heiss, Maria F. C. Burbarelli, Leonardo O. Seno, Rodrigo G. Garcia, Rita T. R. Pietramale and Fabiana R. Caldara
Poultry 2025, 4(4), 48; https://doi.org/10.3390/poultry4040048 - 2 Oct 2025
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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
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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.
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Open AccessArticle
Effects of Caprylic Acid on the Cecal Colonization of Multidrug-Resistant Salmonella Heidelberg and the Cecal Microbiome in Broiler Chickens
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Shijinaraj Manjankattil, Dhananjai Muringattu Prabhakaran, Anup Kollanoor Johny, Claire Peichel, Divek V. T. Nair, Grace Dewi, Jason Langlie, Trevor J. Gould and Annie M. Donoghue
Poultry 2025, 4(4), 47; https://doi.org/10.3390/poultry4040047 - 1 Oct 2025
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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
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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.
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Open AccessArticle
Biosecurity Gaps and Food Production Practices in Subsistence and Differentiated Backyard Poultry Systems in Central Chile
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Víctor Marambio, Francisca Di Pillo, Cecilia Baumberger, Cristobal Oyarzún, Pablo Galdames, Tamara Palma, Pedro Jimenez-Bluhm, Javiera Cornejo, Stacey Schultz-Cherry and Christopher Hamilton-West
Poultry 2025, 4(4), 46; https://doi.org/10.3390/poultry4040046 - 30 Sep 2025
Abstract
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
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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.
Full article
(This article belongs to the Special Issue Biosecurity in Poultry)
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Open AccessArticle
Molecular Characterization of Fowl Adenovirus from Brazilian Poultry Farms
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André Salvador Kazantzi Fonseca, Diéssy Kipper, Nilo Ikuta and Vagner Ricardo Lunge
Poultry 2025, 4(4), 45; https://doi.org/10.3390/poultry4040045 - 28 Sep 2025
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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
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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.
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Open AccessReview
Gut Microbiota—Campylobacter jejuni Crosstalk in Broiler Chickens: A Comprehensive Review
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Bereket Dessalegn, Motuma Debelo, Michael Hess and Wageha A. Awad
Poultry 2025, 4(4), 44; https://doi.org/10.3390/poultry4040044 - 25 Sep 2025
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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
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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.
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Open AccessArticle
Precision Livestock Farming: YOLOv12-Based Automated Detection of Keel Bone Lesions in Laying Hens
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Tommaso Bergamasco, Aurora Ambrosi, Vittoria Tregnaghi, Rachele Urbani, Giacomo Nalesso, Francesca Menegon, Angela Trocino, Mattia Pravato, Francesco Bordignon, Stefania Sparesato, Grazia Manca and Guido Di Martino
Poultry 2025, 4(4), 43; https://doi.org/10.3390/poultry4040043 - 24 Sep 2025
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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
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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.
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Open AccessArticle
Characterization of Antimicrobial Resistance Patterns and Resistance Genes of Enterococci from Broiler Chicken Litter
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Tam T. Tran, Niamh Caffrey, Haskirat Grewal, Yuyu Wang, Rashed Cassis, Chunu Mainali, Sheryl Gow, Agnes Agunos, Sylvia Checkley and Karen Liljebjelke
Poultry 2025, 4(3), 42; https://doi.org/10.3390/poultry4030042 - 12 Sep 2025
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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
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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.
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Open AccessArticle
Broiler Chicken Response to Xylanase and Rice Bran Supplementation in Wheat- and Maize-Based Diets
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Marko Tukša, Stephen C. Mansbridge, Michael R. Bedford, Stephen P. Rose and Vasil R. Pirgozliev
Poultry 2025, 4(3), 41; https://doi.org/10.3390/poultry4030041 - 8 Sep 2025
Abstract
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-
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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.
Full article
Open AccessReview
Genetic Resistance to Newcastle Disease in Poultry: A Narrative Review
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Thiruvenkadan Aranganoor Kannan, Srinivasan Palani, Saravanan Ramasamy, Sivakumar Karuppusamy, Sunday Olusola Peters and Malarmathi Muthusamy
Poultry 2025, 4(3), 40; https://doi.org/10.3390/poultry4030040 - 30 Aug 2025
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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
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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.
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Open AccessReview
Potential Risk Factors Related to Antimicrobial Usage and Antimicrobial Resistance in Commercial Poultry Production—A Scoping Review
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Lena Sonnenschein-Swanson, Silvia Baur-Bernhardt, Annemarie Käsbohrer, Marcus Georg Doherr, Diana Meemken and Petra Weiermayer
Poultry 2025, 4(3), 39; https://doi.org/10.3390/poultry4030039 - 28 Aug 2025
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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
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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.
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Open AccessArticle
Modeling Broiler Discomfort Under Commercial Housing: Seasonal Trends and Predictive Insights for Precision Livestock Farming
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Natalia Coimbra da Silva, Irenilza de Alencar Nääs, Juliana de Souza Granja Barros and Daniella Jorge de Moura
Poultry 2025, 4(3), 38; https://doi.org/10.3390/poultry4030038 - 25 Aug 2025
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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
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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.
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Open AccessArticle
Negative Impact of a Disproportionally Elevated Level of Dietary 25-Hydroxycholecalciferol on the Performance and Meat Yield of Ross 708 Broilers
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Seyed Abolghasem Fatemi and Edgar David Peebles
Poultry 2025, 4(3), 37; https://doi.org/10.3390/poultry4030037 - 14 Aug 2025
Abstract
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
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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.
Full article
(This article belongs to the Collection Poultry Nutrition)
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Open AccessArticle
Effect of Exposing Layer Chicken Embryos to Continuous Green Light During Incubation and Vaccination Method on Early Life Basal Stress and Humoral Immune Response
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Jill R. Domel and Gregory S. Archer
Poultry 2025, 4(3), 36; https://doi.org/10.3390/poultry4030036 - 8 Aug 2025
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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
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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.
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Open AccessArticle
Targeting the Oviduct Microbiota and Redox Status: A Novel Perspective on Probiotic Use in Laying Hens
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Gabriela Miotto Galli, Ines Andretta, Camila Lopes Carvalho, Aleksandro Schafer da Silva and Marcos Kipper
Poultry 2025, 4(3), 35; https://doi.org/10.3390/poultry4030035 - 7 Aug 2025
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(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
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(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.
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Open AccessArticle
Automatic Detection of Foraging Hens in a Cage-Free Environment with Computer Vision Technology
by
Samin Dahal, Xiao Yang, Bidur Paneru, Anjan Dhungana and Lilong Chai
Poultry 2025, 4(3), 34; https://doi.org/10.3390/poultry4030034 - 30 Jul 2025
Abstract
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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
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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.
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Open AccessArticle
Thermoregulatory and Behavioral Responses of Pullets Subjected to High Temperatures and Supplemented with Vitamin D3 and Different Limestone Particle Sizes
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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 and Robson Mateus Freitas Silveira
Poultry 2025, 4(3), 33; https://doi.org/10.3390/poultry4030033 - 29 Jul 2025
Abstract
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
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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.
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(This article belongs to the Topic Effects of Dietary Interventions on Farm Animal Welfare and Production)
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Open AccessArticle
The Expression of Social Behaviors in Broiler Chickens Grown in Either Conventional or Environmentally Modified Houses During the Summer Season
by
Chloe M. O’Brien and Frank W. Edens
Poultry 2025, 4(3), 32; https://doi.org/10.3390/poultry4030032 - 16 Jul 2025
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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
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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.
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Open AccessArticle
Assessment of Pupillometry Across Different Commercial Systems of Laying Hens to Validate Its Potential as an Objective Indicator of Welfare
by
Elyse Mosco, David Kilroy and Arun H. S. Kumar
Poultry 2025, 4(3), 31; https://doi.org/10.3390/poultry4030031 - 15 Jul 2025
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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
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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.
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Open AccessArticle
Validation of the Energy Matrix of Guanidinoacetic Acid for Broiler Chickens: Effects on Performance, Carcass Traits, and Meat Quality
by
Fernanda Danieli Antoniazzi Valentini, Heloísa Pagnussatt, Fernanda Picoli, Letieri Griebler, Carine de Freitas Milarch, Arele Arlindo Calderano, Fernando de Castro Tavernari and Tiago Goulart Petrolli
Poultry 2025, 4(3), 30; https://doi.org/10.3390/poultry4030030 - 14 Jul 2025
Abstract
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
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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.
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