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ABSTRACT: Glyphosate-based herbicides (GBH) are the most extensively used herbicides worldwide. Despite a presumed nondangerousness for animals, several studies reported negative effects after a GBH exposure in several animal models including birds, notably on reproductive functions. Several studies concerning the advantages of Vitamin E (VE) for antioxidant activity but also growth and reproduction have been reported in birds. However, it remains unclear whether VE could alleviate the negative effect of GBHs on chicken ovarian cells. Here we exposed chicken primary granulosa cells (GCs) from F1 and F3/4 follicles to growing doses of GBH (0.036, 0.36, 3.6, and 36 gly eq/L), with or without VE supplementation (1 mg/L) and investigated cell viability, proliferation, oxidative stress and steroidogenesis. GBH exposure did not affect F1 and F3 GCs viability but it increased cell proliferation only in F1 GCs and this effect was not altered by VE. In both F1 and F3/4 GCs, GBH exposure increased total oxidant status (TOS), reduced total antioxidant status (TAS) and consequently increased index of oxidative stress (OSI) in dose dependent manner. This latter effect for GBH 36 mg eq gly/L was totally abolished in response to VE. In both F1 and F3/4 GCs, GBH exposure reduced progesterone secretion in a dose dependent manner and this effect with GBH 0.36 and 1.8 mg eq glyphosate/L was alleviated by VE. However, we did not observe any effect of GBH and VE on the gene expression of several components of the steroidogenesis process. Taken together, these results show that GBH may have endocrine disruptor effects, and that these effects might be alleviated by antioxidant VE supplementation.

ABSTRACT: This study investigated the effects of supplementing the diet of a slow-growing autochthonous chicken breed with dehydrated or live Black Soldier Fly Larvae (BSFL) on meat quality and sensory attributes. The research, conducted at the University of Turin, Italy, involved 144 male birds distributed in three experimental groups. The control group (C) was fed a basal diet in which soybean meal was completely substituted with alternative ingredients. The 2 experimental groups were administered a diet identical to the control group but supplemented with either whole dehydrated black soldier fly larvae (DL) or whole live black soldier fly larvae (LL) at a level equal to 5% expected daily feed intake of dry matter. We evaluated the following parameters: nutrient intake, slaughtering performance, physical and nutritional meat quality, fatty acid composition, proteomics, and sensory characteristics. The results demonstrated BSFL supplementation to have no detrimental effects on overall meat quality or sensory attributes. Specifically, there were no significant differences in physical meat quality parameters, nutritional composition, lipid oxidation, or protein digestibility between control and BSFL-fed groups. Fatty acid analysis revealed higher concentrations of lauric and myristic acids in BSFL-fed chicken breast (p < 0.005), suggesting potential nutritional benefits from the supplement. The proteomic analysis also showed no significant differences in the expression of abundant proteins in the breast meat between groups, indicating minimal physiological impact of BSFL supplementation. Overall, this study provides reassurance to consumers and industries about the suitability of BSFL as a sustainable feed supplement for poultry that also offers potential benefits in terms of optimizing the fatty acid profile of chicken meat.

ABSTRACT: The sensory characteristics of poultry products are crucial in defining their quality and widely influence consumer choices. Even though the scientific literature clearly indicates that for muscle foods the sensory profile is relevant in purchase decisions and overall acceptability, sensory evaluation has often been underestimated and considered complementary to instrumental and/or chemical assessments. Sensory analysis includes different types of validated tests (discriminative, descriptive, and affective), applied depending on the purpose of the research study, requiring special attention in the sample preparation phase, in particular for nonhomogeneous products such as poultry meat, requiring reproducible cutting, cooking and presentation to the tasters. The aim of this paper is to review, critically assess and discuss sensory methods, standardized procedures and sample preparation tailored for chicken meat, through the literature from 2000 to 2023, with a section dedicated to ethical aspects that must be carefully considered when designing a sensory protocol. The target readers are both the research and the business communities, as the information can be widely applied for quality control, to develop new food products, to understand or drive preferences or, for example, to assess potential sensory differences among chickens fed with different diets. To the best of the authors' knowledge, this review represents a useful first guide for those approaching the sensory analysis of chicken meat.

ABSTRACT: This study explores upright versus inverted catching and crating of spent laying hens. Both catching methods were compared using a cost-benefit analysis that focused on animal welfare, ergonomic, and financial considerations. Data were collected on seven commercial farms (one floor system and six aviary systems) during depopulation of approximately 3,000 hens per method per flock. Parameters such as wing flapping frequency, catcher bird interaction, incidence of catching damage and hens dead on arrival (DOA) were measured and compared between catching methods. Ergonomic evaluations were performed via catcher surveys and expert assessment of video recordings. The wing flapping frequency was lower (3.1 ± 0.6 vs. 4.0 ± 0.5, P < 0.001) and handling was gentler (1.9 ± 0.5 vs. 4.4 ± 0.5, P < 0.001), both on a 7-point Likert scale, for upright versus inverted catching. However, more person-hours per 1000 hens were required for upright than inverted catching (8.2 ± 3.2 h vs. 4.8 ± 2.0 h, P = 0.011), with only wing bruises being significantly less common for upright than inverted catching (1.1 ± 0.6 % vs. 1.7 ± 0.7%, P = 0.04). Upright catching was 1.8 times more expensive than inverted catching; compensation for this cost would require a premium price of approximately €0.0005 extra per egg. Ergonomically, both catching methods were considered demanding, although catchers (n = 29) preferred inverted catching. In conclusion, this study showed animal welfare benefits of upright vs. inverted catching. Industry adoption of upright catching will depend on compensation of the additional labor costs, adjustments to labor conditions and shorter loading times.

ABSTRACT: Oxidative stress (OS) is a major concern that impacts the overall health of chickens in modern production systems. It is characterized by an imbalance between antioxidant defence mechanisms and the production of reactive oxygen species (ROS). This literature review aims to provide a comprehensive overview of oxidative stress in poultry production, with an emphasis on its effects on growth performance, immune responses, and reproductive outcomes. This review highlights the intricate mechanisms underlying OS and discusses how various factors, including dietary components, genetic predispositions, and environmental stressors can exacerbate the production of ROS. Additionally, the impact of oxidative stress on the production performance and physiological systems of poultry is examined. The study also emphasizes the relationship between oxidative stress and poultry diseases, highlighting how impaired antioxidant defenses increase bird's susceptibility to infections. The review assesses the existing approaches to reducing oxidative stress in chickens in response to these challenges. This includes managing techniques to lower stress in the production environment, antioxidant supplements, and nutritional interventions. The effectiveness of naturally occurring antioxidants, including plant extracts, minerals, and vitamins to improve poultry resistance to oxidative damage is also examined. To improve the antioxidant defenses of poultry under stress conditions, the activation of cellular homeostatic networks termed vitagenes, such as Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2) is necessary for the synthesis of protective factors that can counteract the increased production of ROS and RNS. Future studies into novel strategies for managing oxidative stress in chicken production would build on these research advances and the knowledge gaps identified in this review.

ABSTRACT: Salmonellosis in poultry is detrimental to the advancement of the breeding industry and poses hazards to human health. Approximately 2,600 Salmonella varieties exist, among which S. Enteritidis, S. Pullorum, S. Typhimurium, and S. Infantis are prevalent serotypes in the poultry industry in recent years. They can also infect humans by contaminating poultry eggs and meat. Therefore, identifying these serotypes is crucial for successful preventive and control interventions. The White–Kauffmann–Le Minor scheme is time-consuming and requires expensive reagents. Whole-genome sequencing (WGS) and other molecular biology techniques require skilled technical staff. In comparison, the polymerase chain reaction (PCR) is more accurate, rapid, and inexpensive, thus proving suitable for widespread application in the poultry industry. Here, we selected 4 specific primers: lygD, mdh, ipaJ, and SIN_02055, which correspond to detecting S. Enteritidis, S. Typhimurium, S. Pullorum, and S. Infantis, respectively. They were integrated into a 1-step multiplex PCR method. We optimized the PCR method by utilizing specificity test results to determine the optimal annealing temperature (57°C). The PCR method exhibited excellent sensitivity for genomic DNA and bacterial cultures. We used the developed method to determine 157 clinical Salmonella isolates from various stages of the poultry production chain. The results aligned with serotype data generated via WGS analysis, demonstrating the method's excellent accuracy. In conclusion, this study developed a 1-step multiplex PCR method that simultaneously identifies S. Enteritidis, S. Typhimurium, S. Pullorum, and S. Infantis, allowing routine mass detection in the grass-root poultry industry.

ABSTRACT: Control of meat quality traits is an important goal of any farm animal production, including poultry. A better understanding of the biochemical properties of muscle fiber properties that drive muscle development and ultimately meat quality constitutes one of the major challenging topics in animal production and meat science. In this paper, the existing classification methods of skeletal muscle fibers in poultry were reviewed and the relationship between contractile and metabolic characteristics of muscle fibers and poultry meat quality was described. Finally, a comprehensive review of multiple potential factors affecting muscle fiber distribution and conversion is presented, including breed, sex, hormones, growth performance, diet, muscle position, exercise, and ambient temperature. We emphasize that knowledge of muscle fiber typing is essential to better understand how to control muscle characteristics throughout the life cycle of animals to better manage the final quality of poultry meat.

ABSTRACT: The need to develop novel alternatives to antibiotics gained prominence following the ban on sub-therapeutic antibiotic applications for livestock growth enhancement. This prohibition led to a surge in research papers exploring potential alternatives to antibiotics to promote growth and health in poultry. As a result, it has become imperative to synthesize information regarding research accomplishments and publication patterns in antibiotic alternatives, to assess research gaps and aid regulatory, funding, and research entities in making informed decisions. Consequently, our study aims to systematically analyze and comprehend the research and publication trends related to growth-promoting antibiotic alternatives in poultry. We identified all publications during the search period from 2009 to 2022, utilizing various bibliometric analysis datasets from Scopus, Web of Science/InCites, and Dimensions. The Rayyan web application was employed for manual deduplicating, labeling, and screening the relevant publications. From an initial pool of 2038 publications, we screened and categorized 816 based on factors such as alternative antibiotic categories, publication years, countries, species, journals, and institutes. Our findings reveal that the most prevalent publications are centered around probiotic (30.51%) and phytogenic (24.02%). Notably, the United States leads publication output, followed by China and Egypt. Among poultry species, broilers emerge as the most extensively studied category, followed by layer chickens. Universities emerge as the foremost contributors to antibiotic alternative research, while government institutes and industry occupy the second and third positions, respectively. Upon scrutinizing the journals responsible for the highest publication count and most cited papers, it became evident that the journal “Poultry Science” leads with the highest percentage (13.51%) and the most highly cited publications, accounting for five out of eleven highly cited articles. This comprehensive review outlines research trends concerning diverse antibiotic alternatives, taking into account poultry species and geographical distribution. The future trajectory in this domain is projected to encompass a blend of various antibiotic alternatives that could be administered as a single product and/or the innovative use of novel antibiotic alternatives.

Microplastics (MPs) are small plastic particles less than five millimeters in size. Microplastic pollution poses a serious threat to ecosystems, affecting both biotic and abiotic components. Current techniques used to eliminate microplastics include recycling, landfilling, incineration, and biodegradation. Microplastics have been detected in various animal species, including poultry, fish, mammals, and invertebrates, indicating widespread exposure and potential bioaccumulation. In the Middle East, MPs contamination was discovered in chicken purchased from food shops, chain supermarkets, and open markets. The contamination levels ranged from 0.03±0.04 to 1.19±0.72 particles per gram of chicken meat. In poultry, microplastics negatively affect production and harm vital organs such as the kidneys, spleen, and lungs. In humans, exposure to microplastics can lead to inflammation, immune responses, metabolic disturbances, DNA damage, neurological damage, and even cancer upon contact with mucosal membranes or absorption into the body. Several studies have explored the use of microorganisms, including bacteria, fungi, and algae, to degrade microplastics, offering an economical and environmentally friendly solution. Different polymers were cultured with strains of Bacillus spp. (SB-14 and SC-9) and Streptococcus spp. (SC-56) for a duration of 40 days. Degradation rates for LDPE were 11.8 %, 4.8 %, and 9.8 %. The rates of deterioration for HDPE were 11.7 %, 3.8 %, and 13.7 %. Rates for polyester beads were 17.3 %, 9.4 %, and 5.8 %. This review focuses on the effects of microorganisms in removing microplastic pollution, the detrimental impact of microplastics on poultry production, and the connection between microplastic pollution and human health.

ABSTRACT: Minimizing the utilization of antibiotics in animal production is crucial to prevent the emergence of antimicrobial resistances. Thus, research on alternatives is needed to maintain productivity, sustainability, and animal health. To gain a comprehensive understanding of probiotics’ modes of action on performance, intestinal microbiota, and gut health in poultry, 3 probiotic strains (Enterococcus faecalis CV1028 [EntF], Bacteroides fragilis GP1764 [BacF], and Ligilactobacillus salivarius CTC2197 [LacS]) were tested in 2 in vivo trials. Trial 1 comprised of a negative control group fed basal diet (BD) and 3 treatment groups that received BD with EntF, BacF and LacS. Trial 2 included a negative control group, a positive control group with Zinc-Bacitracin as antibiotic growth promoter (AGP), and 2 groups treated with a blend of probiotics (EntF+BacF+LacS) during 0 to 10 or 0 to 35 d, respectively. Wheat-soybean-rye based diets without exogenous enzymes were used as a challenge model to induce intestinal mild- or moderate-inflammatory process in the gut.In Trial 1, individually administered probiotics improved FCR at 8 d compared to Control, but these positive effects were lost in the following growing periods probably due to the high grade of challenging diet and a too low dose of probiotics. In Trial 2, both Probiotic treatments, administered only 10 or 35 d, significantly improved FCR to the same extent as of the Antibiotic group at the end of the trial. Although the performance between antibiotic and probiotic mixture showed similar values, microbiota analysis revealed different microbial composition at 7 d, but not at 21 d. This suggests that modes of action of the AGP and the tested probiotic blend differ on their effects on microbiome, and that the changes observed during the first days’ posthatch are relevant on performance at the end of the study. Therefore, the probiotics administration only during the first 10 d posthatch was proven sufficient to induce similar performance improvements to those observed in birds fed antibiotic growth promoters throughout the whole experimental trial.

ABSTRACT: Animals’ individual behavior is commonly monitored by live or video observation by a person. This can be labor intensive and inconsistent. An alternative is the use of machine learning-based computer vision systems. The objectives of this study were to 1) develop and optimize machine learning model frameworks for detecting, tracking and classifying individual behaviors of group-housed broiler chickens in continuous video recordings; and 2) use an independent dataset to evaluate the performance of the developed machine leaning model framework for individual poultry behaviors differentiation. Forty-two video recordings from 4 different pens (total video duration = 1,620 min) were used to develop and train multiple models for detecting and tracking individual birds and classifying 4 behaviors: feeding, drinking, active, and inactive. The optimal model framework was used to continuously analyze an external set of 11 videos (duration = 326 min), and the second-by-second behavior of each individual broiler was extracted for the comparison of human observation. After comparison of model performance, the YOLOv5l, out of 5 detection models, was selected for detecting individual broilers in a pen; the osnet_x0_25_msmt17, out of 4 tracking algorithms, was selected to track each detected bird in continuous frames; and the Gradient Boosting Classifier, out of 12 machine learning classifiers, was selected to classify the 4 behaviors. Most of the models were able to keep previously assigned individual identifications of the chickens in limited amounts of time, but lost the identities throughout an examination period (≥4 min). The final framework was able to accurately predict feeding (accuracy = 0.895) and drinking time (accuracy = 0.9) but subpar for active (accuracy = 0.545) and inactive time (accuracy = 0.505). The algorithms employed by the machine learning models were able to accurately detect feeding and drinking behavior but still need to be improved for maintaining individual identities of the chickens and identifying active and inactive behaviors.

ABSTRACT: Mycotoxin contaminated corn poses a risk to poultry production. Although mycotoxin regulatory guidelines are based on the hazards of individual mycotoxin contamination, feed and feed ingredients may be contaminated with multiple mycotoxins. The objective of this study was to assess mycotoxin co-contamination and its impact on the nutrient content of corn grain. Corn samples (n = 328) originating from various regions in the Southeastern U.S. were quantitatively analyzed for fumonisin (FUM), deoxynivalenol (DON), aflatoxin (AFB1) and zearalenone (ZEA) by HPLC-MS/MS. Nutritional content was analyzed by near-infrared spectroscopy, and color data were collected. All 328 samples were found to be contaminated with at least 1 mycotoxin: 100% contained FUM (19-24,680 µg/kg), 69.82% contained DON (0-9,640 µg/kg), 17.07% contained AFB1 (0–939 µg/kg), and 43.60% had detectable levels of ZEA (0-8,093.5 µg/kg). Most of the samples were contaminated with 2 or more mycotoxins, with only 18.29% of the samples containing a single mycotoxin. 38.41% of the samples had 2 mycotoxins present, 36.59 % had 3 mycotoxins, and 4.88% of the samples had all 4 tested mycotoxins present. Samples contaminated with AFB1 had significantly lower fat (P = 0.007) and lightness (P = 0.007); samples contaminated with DON had significantly higher starch (P < 0.001) and lower protein (P < 0.001). Samples contaminated with FUM had significantly higher protein (P = 0.008) and moisture (P = 0.019) and lower starch (P < 0.001). ZEA contaminated samples had significantly lower starch (P = 0.034). A correlation was observed between mycotoxin contamination and altered nutrient content in corn. This study provides further evidence that co-contamination of mycotoxins is the norm in corn, and that mycotoxin contamination correlates with impacts on the nutrient profile of feed corn.

Providing environmental enrichments that increase environmental complexity can benefit poultry welfare. This Poultry Science Association symposium paper is structured around four themes on 1) poultry preferences and affective states 2) species-specific behavior, including play behavior and the relationship between behavior, activity level and walking ability, 3) environmental enrichment and its relationship with indicators of welfare, and 4) a case study focusing on the application of enrichments in commercial broiler chicken production. For effective enrichment strategies, the birds' perspective matters most, and we need to consider individual variation, social dynamics, and previous experience when assessing these strategies. Play behavior can be a valuable indicator of positive affect, and while we do not yet know how much play would be optimal, absence of play suggests a welfare deficit. Activity levels and behavior can be improved by environmental modifications and prior research has shown that the activity level of broilers can be increased, at least temporarily, by increasing the environmental complexity. However, more research on impacts of enrichments on birds' resilience, on birds in commercial conditions, and on slow(er)-growing strains is needed. Finally, incorporating farmers' expertise can greatly benefit enrichment design and implementation on commercial farms.

ABSTRACT: Eubiotics are water and/or feed additives used in poultry to promote gut health and control enteric burden of pathogens, including Clostridium perfringens. While several eubiotic compounds (ECs) are being introduced commercially, it is essential to devise an in vitro model to screen these compounds to assess their immunomodulatory and antimicrobial properties prior to their testing in vivo. A chicken macrophage cell-line (MQ-NCSU) was used to develop an in vitro model to screen the immunological and anti-C. perfringens properties of 10 ECs: monobutyrin, monolaurin, calcium butyrate, tributyrin, carvacrol, curcumin, green tea extract, rosemary extract, monomyristate, and tartaric acid. An optimal concentration for each EC was selected by measuring the effect on viability of MQ-NCSU cells. Cells were then treated with ECs for 6, 12, and 24 h. and expression of interferon-gamma (IFNγ), interleukin (IL)-1β, IL-6, IL-10, transforming growth factor-beta (TGFβ) and cluster of differentiation (CD40) genes, as well as major histocompatibility complex (MHC)-II protein were evaluated. At 6 h post-stimulation, monobutyrin, calcium butyrate, and green tea extract treatments induced a significant downregulation of IFNγ, IL-6, or IL-1β gene transcription and MHC-II expression, while the IL-10 or TGFβ gene expression in these treatments as well as those receiving rosemary extract and tartaric acid was significantly upregulated, when compared to control, suggesting immunomodulatory properties of these ECs. Finally, pretreatment of macrophages with these selected 5 ECs for 24 h followed by C. perfringens infection showed that monobutyrin, green tea extract, rosemary extract, and calcium butyrate treatments can inhibit bacterial growth significantly at 12 and/or 24 h post-infection, when compared to the control. Collectively, our findings show that ECs possessing immunomodulatory and anti-C. perfringens properties can be selected using an in vitro avian macrophage cell-based model so that such ECs can further be tested in vivo for their disease prevention efficacy.

ABSTRACT: For many species, scales are used to classify discomfort and stress (e.g., facial expression/pain scales). Although a significant number of vertebrates used for scientific purposes are chickens, a corresponding scale for birds has not yet been established. We developed a Stressed Chicken Scale (SCS) to investigate whether it is possible to assess discomfort in a chicken by its body posture. A selective review with additional handsearch was conducted to find suitable parameters for visual stress assessment. Seven potential body signals were identified: Tail and head position, eye closure, beak opening, leg and wing position, and plumage fullness (ruffled or fluffed up feathers). The SCS was evaluated for interobserver reliability with veterinary students (n = 20), using randomized pictures of stressed and unstressed chickens in lateral view (n = 80). Observers were able to identify the body signals on the pictures after a brief training session. Agreement scores for interobserver agreement ranged from κ = 0.31 (fair agreement) for eye closure to κ = 0.78 (substantial agreement) for beak opening. We found that the number of body signals displayed in a stressed expression had an impact on observers' overall assessment of the chickens, for example, chickens were more likely to be rated as stressed if more than 4 signals indicative of stress were present. We conclude that the 7 individual body signals can be used to identify discomfort in chickens.

ABSTRACT: This study aimed to explore the genetic basis of walking ability and potentially related performance traits in turkey purebred populations. Phenotypic, pedigree, and genomic datasets from 2 turkey lines hatched between 2010 and 2023 were included in the study. Walking ability data, defined based on a scoring system ranging from 1 (worst) to 6 (best), were collected on 192,019 animals of a female line and 235,461 animals of a male line. Genomic information was obtained for 46,427 turkeys (22,302 from a female line and 24,125 from a male line) using a 65K single nucleotide polymorphism (SNP) panel. Variance components and heritability for walking ability were estimated. Furthermore, genetic and phenotypic correlations among walking ability, mortality and disorders, and performance traits were calculated. A genome-wide association study (GWAS) was also conducted to identify SNPs associated with walking ability. Walking ability is moderately heritable (0.23 ± 0.01) in both turkey lines. The genetic correlations between walking ability and the other evaluated traits ranged from -0.02 to -0.78, with leg defects exhibiting the strongest negative correlation with walking ability. In the female line, 31 SNPs were associated with walking ability and overlapped with 116 genes. These positional genes are linked to 6 gene ontology (GO) terms. Notably, genes such as CSRP2, DDX1, RHBDL1, SEZ6L, and CTSK are involved in growth, development, locomotion, and bone disorders. GO terms, including fibronectin binding (GO:0001968), peptide cross-linking (GO:0018149), and catabolic process (GO:0009057), are directly linked with mobility. In the male line, 66 markers associated with walking ability were identified and overlapped with 281 genes. These genes are linked to 12 GO terms. Genes such as RB1CC1, TNNI1, MSTN, FN1, SIK3, PADI2, ERBB4, B3GNT2, and BACE1 are associated with cell growth, myostatin development, and disorders. GO terms in the male line are predominantly related to lipid metabolism. In conclusion, walking ability is moderately heritable in both populations. Furthermore, walking ability can be enhanced through targeted genetic selection, emphasizing its relevance to both animal welfare and productivity.

ABSTRACT: Avian feather color is a fascinating trait, and the genetic mechanism of duck plumage formation is still in the preliminary stage. In this study, feather color of Liancheng White ducks was analyzed by determination of melanin content and RNA-seq analysis. In this research, 9 ducks from Mallards (n = 3), Liancheng White (n = 3) and Pekin ducks (n = 3) were used by high performance liquid chromatography (HPLC) and Masson-Fontana staining to reveal the difference of feather melanin content. RNA-seq from 11 hair follicle tissues (1- and 8-wk-old) of Liancheng White ducks (n = 5) and Pekin ducks (n = 7) was used to analyze the candidate genes for the feather melanin synthesis, and Immunofluorescence experiment was used to show the protein expression in 6 black- and white-feathered ducks. Pectorale, skin, liver, fat, brain, heart, kidney, lung, spleen of an 8-wk-old black-feathered Mallard were collected for candidate gene expression. The results showed that the contents of feathers, beak, web melanin in Liancheng White ducks were higher than in Pekin ducks (p < 0.05). Melanin within hair follicles was located in the barb ridge and hair matrix of black feather duck, also we found that TYRP1, TYR, SOX10 genes were differentially expressed between Liancheng White and Pekin ducks (p < 0.05), and these genes were mainly expressed showed in duck skin tissues. This study revealed the unique feather color phenotype of Liancheng White duck shedding light on the transcriptome that underlies it.

ABSTRACT: Microbiome of the gastrointestinal tract (GIT) has been identified as one of the crucial factors influencing the health and condition of domestic animals. The global poultry industry faces the challenge of understanding the complex relationship between gut microbiota composition and performance-related traits in birds. Considerable variation exists in the results of correlational studies using either 16S rRNA profiling or metagenomics to identify bacterial taxa associated with performance, productivity, or condition in poultry (e.g., body weight, growth rate, feeding efficiency, or egg yield). In this review, we survey the existing reports, discuss variation in research approaches, and identify bacterial taxa consistently linked to improved or deteriorated performance across individual poultry-focused studies. Our survey revealed high methodological heterogeneity, which was in contrast with vastly uniform focus of the research mainly on the domestic chicken (Gallus gallus) as a model. We also show that the bacterial taxa most frequently used in manipulative experiments and commercial probiotics intended for use in poultry (e.g., species of Lactobacillus, Bacillus, Enterococcus, or Bifidobacterium) do not overlap with the bacteria consistently correlated with their improved performance (Candidatus Arthromitus, Methanobrevibacter). Our conclusions urge for increased methodological standardization of the veterinary research in this field. We highlight the need to bridge the gap between correlational results and experimental applications in animal science. To better understand causality in the observed relationships, future research should involve a broader range of host species that includes both agricultural and wild models, as well as a broader range of age groups.

ABSTRACT: Salmonella enterica serovar Typhimurium is one of the top Salmonella serovars annually linked to poultry production and corresponding human illnesses. Because of this, vaccination of commercial poultry against Salmonella Typhimurium has been a focal point in recent years. There are several commercially available Salmonella Typhimurium vaccines available for use in poultry production. Among these are modified live vaccines, including Poulvac ST (Zoetis), Megan Egg (AviPro), and Megan Vac 1 (AviPro). In this study, analyses of 27 field isolates of Salmonella Typhimurium from poultry sources indicated evidence for the persistence of some vaccine-origin strains through the commercial production cycle. Further analyses of 26,812 database isolates indicated vaccine-origin isolates are persisting frequently through processing, are present on retail meat products, and are even occasionally found in human patients. A novel polymerase chain reaction (PCR) was created and validated which enables simultaneous identification of Salmonella enterica sp., the Salmonella Typhimurium serovar, and differentiation of wild type Salmonella Typhimurium from live attenuated vaccines involving mutations in the cya/crp or aroA genes. The PCR was developed considering whole genome differences between the vaccines and wild type field isolates and was validated using different field isolates and recovered vaccine strains. This method enables poultry producers to rapidly determine if recovered field isolates have a vaccine origin.

ABSTRACT: Preening cups are a form of environmental enrichment that provides Pekin ducks a semi-open water source to express their natural behaviors. We recently observed that preening cups may increase feather pecking behaviors in ducks. Thus, we set out to determine if this form of enrichment can impact the affective state of Pekin ducks. To accomplish this goal, we evaluated the effect of preening cups on serotonin (5-HT) and dopamine (DA) turnover via mass spectrometry and their respective synthetic enzyme gene expression via qRT-PCR. Our study investigated the link between aggressive pecking with levels and activity of brain 5-HT and DA. Brain 5-HT and DA levels and activity have been established for decades to be associated with affective states. Grow-out Pekin ducks (n = 260) were housed at Purdue and raised per industry standards. On day 18, brains were collected from ducks in pens before preening cups were placed (PRE, n = 6) and, again on day 43, in pens with (PC, n = 6) and without (CON, n = 6) preening cups. Brains were dissected into right and left halves, then further microdissected into 4 brain areas: caudal mesencephalon (CM), rostral mesencephalon (RM), diencephalon (DI), and forebrain (FB). The right hemisphere was used for mass spectrometry to determine the neurotransmitter concentration (ng/mg of tissue) and those concentrations were applied to neurotransmitter turnover equations. There were no differences across treatments for 5-HT turnover in any brain area. There were differences in DA turnover across age (P = 0.0067) in the CM and across treatments (P = 0.003) in the RM. The left hemisphere of the brain was used to perform qRT-PCR on the genes of 5-HT and DA production enzymes. Within the CM, day 43 duck brains had increased (P = 0.022) tryptophan hydroxylase and tyrosine hydroxylase relative mRNA levels. All other brain areas showed no differences. Our data suggest that ducks housed with preening cups and that showed increased feather pecking are associated with increased brain DA activity. The increased DA in the brain may lead to a predisposition for increased aggression in the form of feather pecking.

ABSTRACT: Improving productive performance is a daily challenge in the poultry industry. Developing cost-effective additives and strategies that improve performance in antibiotic-free poultry production is critical to maintaining productivity and efficiency. This study evaluates the influence of a commercially available phytogenic feed additive (CA-PFA, that comprises silymarin, betaine and curcumin extracts as main ingredients) and silymarin on commercial broilers' productive performance and liver function with and without carbon tetrachloride (CCl4)-induced liver damage. The experiment was conducted in a completely randomized design, with six treatments, eight replicates, and eight birds per replicate in 18 one-day-old male broilers (Cobb Vantress 500) each; under a 3 × 2 factorial arrangement (3 diets x 2 levels of CCl4, 0 and 1 mL/kg body weight orally). The experimental treatments included 3 diets, commercially recommended doses of CA-PFA (500 mg/kg of feed; this dose provides 70 mg/kg of silymarin, besides the other active ingredients included in the formulation), silymarin (250 mg/kg of feed, containing 28% of active ingredient; this dose provides 70 mg/kg of silymarin as active ingredient) and an additive-free basal diet as a control. A standard commercial silymarin was used as a reference due to its well-known and extensively studied hepatoprotective properties that can mitigate the negative effects of CCl4 in the liver. The data were analyzed as a 2-way ANOVA, and the means showing significant (P ≤ 0.05) differences were then compared using the Post-Hoc Tukey HSD test. No interaction was detected between factors. Exposure to CCl4 had a noticeable detrimental effect on alertness, productive performance, and liver function of broilers without a significant increase in mortality. Including CA-PFA in the diet improved productive performance compared to the basal diet from day 21 to the end of the trial, on day 42. While no influence in feed intake was detected for any treatment, CA-PFA improved body weight gain (BWG) and feed conversion ratio (FCR) significantly (P < 0.05) from day 21 to the end of the trial in healthy and CCl4-exposed birds. The results show that CA-PFA supplementation improves performance parameters in broilers with and without CCl4-induced liver damage, when compared to a basal diet and the addition of a standard commercial silymarin product.

ABSTRACT: Over the past years, the poultry industry has been assigned to greater production performance but has become highly sensitive to environmental changes. The average world temperature has recently risen and is predicted to continue rising. In open-sided houses, poultry species confront high outside temperatures, which cause heat stress (HS) problems. Cellular responses are vital in poultry, as they may lead to identifying confirmed HS biomarkers. Heat shock proteins (HSP) are highly preserved protein families that play a significant role in cell function and cytoprotection against various stressors, including HS. The optimal response in which the cell survives the HS elevates HSP levels that prevent cellular proteins from damage caused by HS. The HSP have chaperonic action to ensure that stress-denatured proteins are folded, unfolded, and refolded. The HSP70 and HSP90 are the primary HSP in poultry with a defensive function during HS. HSP70 was the optimal biological marker for assessing HS among the HSP studied. The current review attempts to ascertain the value of HSP as a heat stress defense mechanism in poultry.

ABSTRACT: Essential oils (EO), ascorbic acid, sugars, carotenoids, flavonoids, dietary fiber, polyphenols, and trace minerals are found in citrus residue. It gives animals energy and promotes health. On a dry matter basis, the citrus pulp is composed of 7% crude protein, 14% crude fiber, 21.6% nitrogen detergent fiber, 2.5% fat, 24.4% total sugars, and 12.1% ME MJ/kg. It has been reported that the natural antioxidant content of citrus pulp has a beneficial effect on growth and microbial and immunological parameters. The literature indicates that the ultimate weight and weight gain of poultry are significantly (P > 0.05) greater with 7.5% inclusion. Growing knowledge of the health benefits of lactic acid bacteria (LAB) in producing beneficial metabolites has led to interest in developing LAB-containing products for use in biofeed businesses. The consumption of fermented citrus residue significantly decreased blood cholesterol levels. Fermentation results in the production of many compounds (including organic acids, exopolysaccharides, bioactive peptides, phenolic compounds, and gamma-aminobutyric acid), which have many multidimensional functions for maintaining the health and well-being of poultry. During fermentation, the pH may quickly decrease, and harmful bacterial and fungal organisms may be substantially retarded at the early stage of ensiling. The published literature has shown that the fermentation of citrus waste with different probiotic strains, such as Lactobacillus acidophilus, Limosilactobacillus fermentum, Lactiplantibacillus plantarum, Pediococcus pentocaseus, and Lacticaseiobacillus paracasei, in the diet has fantastic effects on the conversion of citrus waste into fermented high-quality feed with extended shelf life and sensory value. Citrus waste lactic acid fermentation may be a viable option for producing nutritional biofeed for poultry, but there is a lack of related research on poultry, so more research on food-grade bacterial fermentation is needed.

ABSTRACT: Salmonella and Campylobacter are common bacterial hazards causing foodborne illnesses worldwide. A large proportion of Salmonella and Campylobacter illnesses are attributed to contaminated poultry products that are mishandled or under cooked. Processing interventions such as chilling and post-chill dip are critical to reducing microbial contamination of poultry. A comprehensive search of the literature published between 2000 and 2021 was conducted in the databases Web of Science, Academic Search Complete, and Academic OneFile. Studies were included if they were in English and investigated the effects of interventions against Salmonella and/or Campylobacter on whole carcasses and/or parts during the chilling or post-chill stages of poultry processing. Random-effects meta-analyses were performed using the “meta” package in the R programming language. Subgroup analyses were assessed according to outcome measure reported, microorganism tested, processing stage assessed, and chemical treatment used. The results included 41 eligible studies. Eighteen studies reported results of 28 separate interventions against Salmonella and 31 reported results of 50 separate interventions against Campylobacter. No significant difference (P> 0.05) was observed when comparing the combined mean difference of all interventions targeting Salmonella to the combined mean difference of all interventions targeting Campylobacter or when comparing chilling times within each pathogen subgroup. For analyses examining antimicrobial additives, peroxyacetic acid (PAA) had the largest reduction against Salmonella population regardless of chilling time (P< 0.05). PAA also had the largest reduction against Campylobacter population and prevalence during primary chilling (P< 0.01). Air chilling showed a lower reduction for Campylobacter than any immersion chilling intervention (P< 0.05). Chilling time and antimicrobial used during poultry processing had varying effects depending on the pathogen and outcome measure investigated (concentration or prevalence). High heterogeneity and low sample numbers in most analyses suggest that more high-quality research that is well-designed and has transparent reporting of methodology and results is needed to corroborate the results.

ABSTRACT: Contamination of feed with mycotoxins has become a severe issue worldwide. Among the most prevalent trichothecene mycotoxins, T-2 toxin is of particular importance for livestock production, including poultry posing a significant threat to animal health and productivity. This review article aims to comprehensively analyze the pathological consequences, metabolism, and toxic effects of T-2 toxin in poultry. Trichothecene mycotoxins, primarily produced by Fusarium species, are notorious for their potent toxicity. T-2 toxin exhibits a broad spectrum of negative effects on poultry species, leading to substantial economic losses as well as concerns about animal welfare and food safety in modern agriculture. T-2 toxin exposure easily results in negative pathological consequences in the gastrointestinal tract, as well as in parenchymal tissues like the liver (as the key organ for its metabolism), kidneys, or reproductive organs. In addition, it also intensely damages immune system-related tissues such as the spleen, the bursa of Fabricius, or the thymus causing immunosuppression and increasing the susceptibility of the animals to infectious diseases, as well as making immunization programs less effective. The toxin also damages cellular processes on the transcriptional and translational levels and induces apoptosis through the activation of numerous cellular signaling cascades. Furthermore, according to recent studies, besides the direct effects on the abovementioned processes, T-2 toxin induces the production of reactive molecules and free radicals resulting in oxidative distress and concomitantly occurring cellular damage. In conclusion, this review article provides a complex and detailed overview of the metabolism, pathological consequences, mechanism of action as well as the immunomodulatory and oxidative stress-related effects of T-2 toxin. Understanding these effects in poultry is crucial for developing strategies to mitigate the impact of the T-2 toxin on avian health and food safety in the future.

ABSTRACT: The adverse effects of exposure to fine particulate matter (PM2.5) on body health have attracted global public attention. However, there is limited research on PM2.5 in animal houses. Numerous studies have indicated that long-term exposure to high levels of PM2.5 can cause damage to multiple systems in animals. Poultry houses are one of the primary sources of PM2.5 emissions. However, there is limited research on the effects of PM2.5 exposure on poultry organisms. This study analyzed the histopathological changes in the lung tissue of poultry under PM2.5 exposure conditions. It used the LC–MS method to analyze the alterations in the serum metabolomic profile of poultry. This study confirmed that long-term exposure to high levels of PM2.5 had significantly reduced the growth performance of poultry. Histopathological slides of the lung tissue in chickens exposed to long-term retention of PM2.5 clearly showed significant damage. Furthermore, the serum metabolome analysis revealed significant changes in the serum metabolic profile of chickens exposed to long-term PM2.5 exposure. Specifically, there were notable alterations in the Glycerophospholipid metabolism, Steroid hormone biosynthesis, and Phenylalanine, tyrosine, and tryptophan biosynthesis pathways.

ABSTRACT: It has been hypothesized that reducing the bioenergetic costs of gut inflammation as an explanation for the effect of antibiotic growth promoters (AGPs) on animal efficiency, framing some observations but not explaining the increase in growth rate or the prevention of infectious diseases. The host's ability to adapt to alterations in environmental conditions and to maintain health involves managing all physiological interactions that regulate homeostasis. Thus, metabolic pathways are vital in regulating physiological health as the energetic demands of the host guides most biological functions. Mitochondria are not only the metabolic heart of the cell because of their role in energy metabolism and oxidative phosphorylation, but also a central hub of signal transduction pathways that receive messages about the health and nutritional states of cells and tissues. In response, mitochondria direct cellular and tissue physiological alterations throughout the host. The endosymbiotic theory suggests that mitochondria evolved from prokaryotes, emphasizing the idea that these organelles can be affected by some antibiotics. Indeed, therapeutic levels of several antibiotics can be toxic to mitochondria, but subtherapeutic levels may improve mitochondrial function and defense mechanisms by inducing an adaptive response of the cell, resulting in mitokine production which coordinates an array of adaptive responses of the host to the stressor(s). This adaptive stress response is also observed in several bacteria species, suggesting that this protective mechanism has been preserved during evolution. Concordantly, gut microbiome modulation by subinhibitory concentration of AGPs could be the result of direct stimulation rather than inhibition of determined microbial species. In eukaryotes, these adaptive responses of the mitochondria to internal and external environmental conditions, can promote growth rate of the organism as an evolutionary strategy to overcome potential negative conditions. We hypothesize that direct and indirect subtherapeutic AGP regulation of mitochondria functional output can regulate homeostatic control mechanisms in a manner similar to those involved with disease tolerance.

ABSTRACT: The experiment was implemented to assess the influence of dietary supplementation of laying quails with creatine monohydrate (CrM), L-carnitine (CAR) and their mixture (CrMCAR) as antioxidants against oxidative stress (OS) induced by 2.5 ppm lead acetate (LA) in drinking water on productive, physiological and microbial aspects. In total, 400 laying quail females at 10 wk of age were divided into a randomized design with 5 groups and 4 replicates of 20 birds each. Birds were fed ad libitum with a balanced diet for 8 wk. The control group was kept under no-stress conditions and was given fresh water without any additives (G1). While birds in other groups were exposed to OS induced experimentally by 2.5 ppm LA in drinking water with no feed additive (G2) or supplemented with 500 mg/kg CrM (G3) or 500 mg/kg CAR (G4) or combination of 250 mg/kg each of CrM and CAR (CrMCAR, G5) to feed mixture.Compared to G2, G5 demonstrated the reduction (P ≤ 0.05) of feed conversion ratio, feed intake, mortality and ileal total coliform, as well as serum and egg malondialdehyde and serum lipid hydroperoxide, uric acid, glucose, cholesterol, enzymatic activities (alanine aminotransferase, aspartate transaminase, alkaline phosphatase, creatine phosphokinase, γ-glutamyl transferase), and heterophils/lymphocytes ratio. In the meanwhile, there was an increase (P ≤ 0.05) in egg production, egg mass, and weight with the improvement of egg quality, serum sex hormones level and ileal lactic acid bacteria for G5 followed by G4 and G3. Moreover, G5 enhanced (P ≤ 0.05), the total antioxidant capacity of egg and serum glutathione, superoxide dismutase, catalase, glutathione peroxidase, protein and calcium levels. Therefore, dietary CrMCAR, CAR and CrM have analogous influence to control by improving the antioxidant and physiological parameters which resulted in better productive performance and egg characteristics of stressed quails. These antioxidants, especially in their equal combination, are beneficial to alleviate oxidative stress incidence and can be recommended for poultry feeding under various aspects of environmental stresses.

ABSTRACT: Infectious bronchitis virus (IBV) is prevalent in Pakistan causing enormous economic losses. To date no clear data are available on circulating genotypes and phylogeographic spread of the virus. Hence current study assessed these parameters for all available IBV Pakistani isolates, based on the 9 new sequences, with respect to other Asian and non-Asian countries. Results indicated that all Pakistani isolates belonged to genotype I (GI), with more than half of them (16/27) belonging to the GI-24 lineage, against which no vaccine is available. Three possible introduction events of the GI-13 IBV lineage into Pakistan, based on the estimated IBV population using isolates from this study, were observed possibly from Afghanistan, China, and/or Egypt. These events were further analyzed on the S1 amino acid level which showed unique alterations (S250H, T270K, and Q298S) in 1 isolate (IBV4, GI-13) when compared to GI-1 lineage. Both GI-1 and GI-13 Pakistani strains showed close homology with homologous vaccine strains that are used in Pakistan. For GI-24 strains, none of the used vaccines showed substantial homology, necessitating the need for further exploration of this lineage and vaccine design. In addition, our findings highlight the importance of genomic surveillance to support phylogeographical studies on IBV in genotyping and molecular epidemiology.

ABSTRACT: Ectoparasite infestations significantly impact the health and productivity of poultry. Chemical applications, although common for pest control, lead to pesticide residues and parasite resistance in poultry. Nanoemulsion-based plant essential oil formulations (NEOFs) provide a promising alternative for controlling poultry ectoparasites. This study aimed to assess the efficacy of NEOFs from clove, cinnamon, and turmeric essential oils (EOs) against ectoparasites, Menopon gallinae and Megninia ginglymura, under laboratory conditions. The toxicity and repellent properties of the NEOFs were examined, with the major chemical compounds of the EOs analyzed using chromatography mass spectrometer. Results identified eugenol as the dominant component in clove and cinnamon EOs (84.60 and 75.19%, respectively), while turmerone (68.46%) was the major compound in turmeric EO. NEOFs with clove:cinnamon:turmeric ratios of 4:0:0, 2:2:0, and 2:0:2 had particle size of 20.76 nm, 20.66 nm, and 89.56 nm, respectively, while those based on eugenol and turmerone standards had sizes

ABSTRACT: Salmonella spp. is a prevalent pathogen that causes great public health concern worldwide. Bacteriophage-based cocktails have arisen as an alternative to antibiotics to inhibit the growth of Salmonella. However, the bactericidal effect of bacteriophage cocktails in vivo largely differs from their observed effect in vitro. This is partly because in vitro developments of cocktails do not always consider the bacterial diversity nor the environmental conditions where bacteriophages will have to replicate. Here, we isolated and sequenced 47 bacteriophages that showed variable degrees of lytic activity against 258 Salmonella isolates from a commercial broiler company in Brazil. Three of these bacteriophages were characterized and selected to assemble a cocktail. In vitro quantitative assays determined the cocktail to be highly effective against multiple serovars of Salmonella, including Minnesota and Heidelberg. Remarkably, the in vitro lytic activity of the cocktail was retained or improved in conditions that more closely resembled the chicken gut, such as anaerobiosis, 42°C, and Salmonella mono-strain biofilms. Analysis of bacterial cross-resistance between the 3 bacteriophages composing the cocktail revealed limited or no generation of cross-resistance. Our results highlight the relevance of an optimized flux of work to develop bacteriophage cocktails against Salmonella with high lytic efficacy and strong potential to be applied in vivo in commercial broiler farms.

ABSTRACT: The impact of global warming on poultry production has gained significant attention over the years. However, our current knowledge and understanding of the mechanisms through which heat stress (HS) resulting from global warming affects the welfare, behavior, immune response, production performance, and even transgenerational effects in poultry are still incomplete. Further research is needed to delve deeper into these mechanisms to gain a comprehensive understanding. Numerous studies have investigated various biomarkers of stress in poultry, aiming to identify reliable markers that can accurately assess the physiological status and well-being of birds. However, there is a significant amount of variation and inconsistency in the results reported across different studies. This inconsistency highlights the need for more standardized methods and assays and a clearer understanding of the factors that influence these biomarkers in poultry. This review article specifically focuses on 3 main aspects: 1) the neuroendocrine and behavioral responses of poultry to HS, 2) the biomarkers of HS and 3) the impact of HS on poultry production that have been studied in poultry. By examining the neuroendocrine and behavioral changes exhibited by poultry under HS, we aim to gain insights into the physiological impact of elevated temperatures in poultry.

ABSTRACT: Impact of traditional halal meat production without stunning (NST) and commercial slaughter with electrical stunning (ST) of 100 slow-growing broiler chicken on blood plasma and different biochemical, enzymatic, hormonal, meat quality, and proteomic changes was evaluated. The results revealed lower (P < 0.05) postmortem pH values and higher redness (a*) scores for ST samples relative to NST group. Myofibrillar fragmentation index and bleeding efficiency (%) were lower (P < 0.05) in ST compared to NST samples. The ST group had higher (P < 0.05) creatinine, total protein, alanine aminotransferase (ALT), and triiodothyronine (T3) than NST group, however, no difference (P > 0.05) in blood glucose, lactate dehydrogenase (LDH), creatine kinase (CK), thyroxine (T4), cortisol, and aspartate aminotransferase (AST) was observed relative to NST samples. The 2-dimensional gel electrophoresis (2-DE) coupled to MALDI-TOF MS of meat samples has identified 14 differentially abundant proteins between 2 groups. Proteins demonstrating positive correlation with stress namely adenylate kinase isoenzyme-1, Rho guanine nucleotide exchange factor (NST), and apolipoprotein A-I (ST) were overabundant. From the current study, it is concluded that electrical stunning of broilers prior to slaughter or traditional halal slaughter without stunning does not adversely affect the meat quality.

ABSTRACT: To investigate the contamination status, serotype distribution, and drug resistance of Salmonella in poultry sold in Jiading District, Shanghai. Four types of raw poultry meats (chickens, ducks, geese, and pigeons) have been sampled from commercial markets, and potential Salmonella contamination has also been isolated and identified via serotype analysis. Furthermore, resistance of isolated Salmonella toward 14 commonly used antibiotics has also been conducted. Ninety-two Salmonella strains were isolated from 236 commercial poultry samples. The detection rates of Salmonella in pigeon, goose, duck, and chicken were 28.89, 44.44, 39.34, and 38.30%, respectively. The detection rate of Salmonella exhibits considerable variation across different years. The serotype composition of Salmonella in poultry demonstrates annual variability, undergoing significant changes from year to year. The majority serotypes of Salmonella have been revealed as S. Typhimurium, S. Enteritidis, and S. Agona. Relatively higher drug resistance was discovered with nalidixic acid, tetracycline, ampicillin and chloramphenicol, with drug resistance rate as 58.70, 53.25, 44.57, and 38.04%, respectively. Low drug resistance was revealed with cefotaxime, and completely sensitive to imipenem. Significant difference in drug resistance was noted in the Salmonella isolated from meats. Different serotypes of Salmonella strains have also revealed as difference in drug resistance. A total of 15.22% of Salmonella strains were nonresistant to any tested drugs. Multidrug-resistant strains accounted for 36.96% of isolated strains. The highest number of resistant antibiotics can reach 12 kinds of different antibiotics, Salmonella resistance is exhibiting a consistent upward trend overall. AMP-TET or CHL-CFZ drug resistance pattern suggested that the strain was multidrug resistant. The contamination of Salmonella in raw poultry meat samples in Jiading District, Shanghai is serious, and the drug resistance is increasing. The measures taken for epidemic prevention and control have a certain impact on the contamination of Salmonella in poultry meat. Therefore, monitoring and control should be strengthened.

ABSTRACT: Locomotor disorders caused by multidrug-resistant (MDR) bacterial pathogens denote one of the most detrimental issues that collectively threaten the poultry industry leading to pronounced economic losses across the world. Hence, searching for effective alternatives, especially those extracted from plant origins became of great priority targeting a partial or complete replacement of chemical antimicrobials to tackle their developing resistance. Therefore, we aimed to determine the prevalence and antimicrobial resistance of Staphylococcus aureus (S. aureus), Salmonella species, Mycoplasma synoviae (M. synoviae), and Escherichia coli (E. coli) recovered from 500 broilers and ducks (250 each) with locomotor disorders in various farms in Dakahlia and Sharkia Governorates, Egypt. Additionally, we assessed, for the first time, the in vitro antimicrobial effectiveness of marjoram, garlic, ginger and cinnamon essential oils (EOs) against MDR and multivirulent bacterial isolates as well as the in vivo efficiency of the most effective antibiotics and EOs either separately or in combination in the treatment of experimentally induced poultry leg disorders. The overall prevalence rates of S. aureus, E. coli, Salmonella species, and M. synoviae were 54, 48, 36, and 2%, respectively. Salmonella species and S. aureus prevailed among ducks and broilers (36 and 76%, respectively). Notably, MDR was observed in 100, 91.7, 81.1, and 78.5% of M. synoviae, E. coli, Salmonella, and S. aureus isolates, respectively. Our in vitro results displayed that marjoram was the most forceful EO against MDR and multivirulent chicken vancomycin-resistant S. aureus (VRSA) and duck S. Typhimurium isolates. The current in vivo results declared that marjoram in combination with florfenicol or amoxicillin/clavulanic acid succeeded in relieving the induced duck and chicken leg disorders caused by S. Typhimurium and VRSA, respectively. This was evidenced by improvement in the clinical and histopathological pictures with a reduction of bacterial loads in the experimental birds. Our encountered successful in vitro and in vivo synergistic effectiveness of marjoram combined with florfenicol or amoxicillin/clavulanic acid recommends their therapeutic application for leg disorders and offers opportunities for reducing the antibiotics usage in the poultry industry.

ABSTRACT: The H6N2 subtype avian influenza virus (AIV) is commonly detected in the migratory waterfowl reservoirs. Previously, H6N2 AIV was believed to be nonpathogenic to young chickens and could not infect or shed in their respiratory tract under experimental conditions. However, in present study, a highly recombinant strain of duck-derived H6N2 AIV was discovered and isolated for pathogenicity tests. The results revealed that H6N2 could induce seroconversion in chickens and high morbidity of over 86.7%, along with evident upper respiratory tract hemorrhage. Moreover, 5 substitutions were detected in the upper respiratory tract shedding reisolated virus, with a high viral load in the target organs of infected chickens. In contrast, ducks failed to exhibit any symptoms, pathological lesions, or viral shedding, while demonstrated seroconversion and high viral load in the livers. These findings indicate that H6N2 AIV could also show pathogenicity to chickens under experimental conditions, thereby effectively replicating and shedding in chickens. Therefore, the study provides further elucidations on the pathogenicity of H6N2 AIV.

ABSTRACT: Poultry activity measurements are often associated with expensive equipment or time-consuming behavior observations. Since low-cost accelerometers are available, the current study validated the FitBark (FitBark 2, FitBark Inc., Kansas City, MO) accelerometer for use on 30 to 32-d-old male Ross 708 broilers. The FitBark provides aggregated activity levels based on tri-axial accelerometer technology. Broilers were housed in 5 rooms, each divided into 12 2 × 2.3 m pens (60 birds per pen, 31 kg m−2 final density). From 30 to 32 d, 1 broiler per room (n = 5) was randomly selected and equipped with a 13 g FitBark. Elastic loops were placed around the wings to secure the FitBark medially on the back. During the same time, validity was assessed via ceiling-mounted video cameras. The video recordings were analyzed using 20-min continuous sampling during the photo phase at 8 time periods per bird. Behavior was assessed every second using an ethogram (9,600 data points per bird). In the first step, the FitBark data were matched and correlated with the corresponding video-based observed activity (OA) data. The FitBark and OA data were not normally distributed (1-sample KS test, all n = 800, ZFitBark = 0.21, ZOA = 0.24, all P < 0.001). Therefore, data were transformed, and a repeated measures correlation was performed for each bird, showing a positive correlation between the FitBark and OA data (rrm = 0.76, 95% CI = 0.72−0.78, df = 794, P < 0.001). In the second step, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. The FitBark correctly identified 91% (sensitivity) of the active and 74% (specificity) of the inactive birds. When the FitBark detected an active or inactive bird, there was a probability of 89% (PPV) and 78% (NPV) that the bird was observed to be active or inactive based on the OA data. Accuracy was at 86%. Overall, FitBark are useful for 1-min interval activity measurements in 30 to 32-d-old male Ross 708 broilers. Further research should focus on validating the FitBark at other ages and in different poultry species.

ABSTRACT: Salmonella represents a food safety concern worldwide. Despite the application of National Control Programs (NCP) against Salmonella, regulated by the European Union, every year the European Food Safety Authority reports new cases. On the look for new alternatives to antibiotics, bacteriophages, or phages, rise as a promising alternative to treat multidrug resistance infections. Although they are known to be ubiquitous in the environment, their high specificity to host cells hinders their isolation and usage for phage therapy. The ISO 6579-1:2017 is performed as a reference method in the NCP and uses an unspecific media to enrich the sample the same way most phage isolation protocols do. Later, the protocol uses a more selective media to isolate the Salmonella, Modified Semisolid Rappaport Vassiliadis (MSRV). This paper aims to find out whether, due to the similarity between phage isolation protocols and the ISO 6579-1:2017, this last one could be used as a protocol to also isolate phages against the same bacterium that is being simultaneously isolated. To do so, 2 experiments were performed to assess phage isolation from MSRV media in in-vivo conditions. The results from experiments 1 and 2 proved that the MSRV media was usable for simultaneous phage and pathogen isolation through a single procedure. Additionally, there is a correlation between the antigenic formulae from the bacteria and the phage's host range, seeming to be effective against bacteria with similar antigenic formulae.

ABSTRACT: Mineralized eggshell is a unique and protective structure in an avian egg. Among different eggshell layers, the cuticle layer is an outermost layer and plays a critical role in protection against bacterial infection. Although the importance of nanosphere in the cuticle layer on the antimicrobial function has been widely accepted, the detailed nanostructure of the cuticle layer in the major poultry species has not been investigated. In the current study, eggs from Japanese quail, commercial layer chickens, mixed breed turkeys, and White Pekin ducks were collected. To investigate the nanostructure throughout the cuticle layer, images of the cross-sectional cuticle layer were taken using a scanning electron microscope (SEM). Unlike the cuticle layer in ducks showing deformed bunched nanospheres, clearly separated nanospheres were present throughout the cuticle layer in quail, chickens, and turkeys. The average size of the nanosphere was the biggest in turkeys and similar between quail and chickens. Most importantly, the size of nanospheres was increased as they ascended from the bottom of the cuticle layer in quail, showing a positive correlation between the size and distance of the nanospheres. However, different sizes of nanospheres were randomly distributed throughout the cuticle layer in chickens and turkeys, showing a weak correlation in chickens and no correlation in turkeys between the size and distance of nanospheres. These new findings in different nanostructures of the cuticle layers in quail, chickens, turkeys, and ducks will serve as a new foundation to better relate their structures with functions.

ABSTRACT: Major viral infections, such as Newcastle disease virus, infectious bronchitis virus, avian influenza virus, and infectious bursal disease virus, inflict significant injury to small poultry and tremendous economic damage to the poultry sector. This research aims to develop a multiplex reverse transcriptase polymerase chain reaction (m-RT-PCR) approach to simultaneously determine these important viral pathogens. The conserved segment of various viral genetic sequences was used to design and synthesize specific primers. Moreover, as positive controls, recombinant vectors were synthesized in this investigation. The d-optimal approach was used to improve PCR conditions in this investigation. Positive controls and clinical samples were used to assess the m-PCR assay's specificity, sensitivity, repeatability, and reproducibility. According to the sensitivity test findings, the m-PCR technique could generate the 8 target genes from viral genomes using 1 × 102. In addition, 8 viral pathogens were detected from the infected samples. The findings also suggest that live animal oral swabs were not significantly different from tissue sampling of a dead animal (P < 0.05), and this kit had a high sensitivity for analyzing both types of samples. The suggested m-PCR test may detect and evaluate viral infection in birds with excellent specificity, sensitivity, and throughput.

ABSTRACT: Meat from broilers raised without the use of antibiotics is becoming increasingly popular among consumers. Consequently, interest in the microbial profiling of chickens produced under nonconventional practices is growing, however, research on this topic is lacking. The current study was designed to characterize the dynamics of gut microbial populations of broilers raised under conventional and no antibiotics ever (NAE) practices. Four commercial farms (2 conventional and 2 NAE) were included in this study. On each farm, cecal (n = 224) and ileal (n = 224) contents were collected from birds at different stages during the grow out of a single flock and following transportation to the processing facility. Cecal microbiota was dominated by the genera Escherichia and Enterococcus upon hatching in both conventional and NAE flocks, shifting with time toward predominantly Faecalibacterium and Bacteroides. The composition of cecal microbial communities of NAE broilers was different than that of conventional chickens (P ≤ 0.05). Conventional broilers harbored a rich, but less diverse cecal microbiota than NAE, while the ileal microbiota was primarily populated with genera previously named Lactobacillus, which exhibited a higher abundance in NAE broilers (P ≤ 0.05). In both production systems, the microbiota followed a similar temporal succession that was more evident in the ceca. Transportation to the processing plant impacted the microbial composition of the ileum (P ≤ 0.05), characterized by an increase in the relative abundance of Psychrobacter. Finally, differential abundance analysis showed a positive correlation between Campylobacter and Enorma within the cecum microbiota, and a negative correlation with Salmonella.

ABSTRACT: Poultry is one of the most commonly farmed species and the most widespread meat industries. However, numerous poultry flocks have been long threatened by pathogenic bacterial infections, especially antimicrobial resistant pathogens. Here the prevalence and the antimicrobial resistance (AMR) profiles of bacterial pathogens isolated from poultry in Jiangxi Province, China were investigated. From 2020 to 2022, 283 tissue and liquid samples were collected from clinically diseased poultry, including duck, chicken, and goose, with an overall positive isolation rate of 62.90%. Among all the 219 bacterial isolates, 29 strains were gram-positive and 190 strains were gram-negative. Major bacteria species involved were avian pathogenic Escherichia coli (APEC; 57.53%; 126/219), followed by Salmonella spp. (11.87%, 26/219), Pasteurella multocida (6.39%, 14/219), and Staphylococcus spp. (1.22%, 11/219). Antimicrobial susceptibility testing showed the APEC isolates displayed considerably higher levels of AMR than the Salmonella and P. multocida isolates. The APEC isolates showed high resistance rate to amoxicillin (89.68%), ampicillin (89.68%), and florfenicol (83.33%), followed by streptomycin (75.40%), cefradine (65.87%), and enrofloxacin (64.29%). Multidrug-resistant isolates were observed in APEC (99.21%), Salmonella spp. (96.16%), and P. multocida (85.71%), and nearly 3 quarters of the APEC strains were resistant to 7 or more categories of antimicrobial drugs. Moreover, blaNDM genes associated with carbapenemase resistance and mcr-1 associated with colisitin resistance were detected in the APEC isolates. Our findings could provide evidence-based guidance for veterinarians to prevent and control bacterial diseases, and be helpful for monitoring the emerging and development of AMR in poultry bacterial pathogens.

ABSTRACT: A total of 45 samples of vaccinated and non-vaccinated layer chickens were collected from farms in the Egyptian governorates of Sharqia, Ismailia, Menofia, Gharbia, Kafr El Sheikh, Qalyubia, and Dakahlia in the year 2022. They exhibited nodular lesions on their combs, mouth corners, and eyelids, suggesting they were infected with pox disease, which was associated with a 3 to 5% mortality rate. The samples were grown on the chorioallantoic-membrane of embryonated chicken eggs to ensure their viability. In both vaccinated and non-vaccinated farms, 35 of 45 virus isolates were confirmed positive via polymerase chain reaction (PCR) of fpv167 (P4b), based on the amplicon length of the fpv167 gene locus. The 6 strains from various Egyptian governorates were chosen for sequencing and genetic characterization. Phylogenetic investigation of the fpv167 (P4b) gene of sequenced strains clustered within sub clade A1 showed 100% correlation between FWPVD, TKPV13401 and fowlpox-AN2, fowlpox-AN3, and fowlpox-AN6, but only a 98.6% correlation between fowlpox-AN1, fowlpox-AN4, and fowlpox-AN5. Comparing the fowlpox-AN1, fowlpox-AN4, and fowlpox-AN5 strains with commercial vaccine strains (HP1-444-(FP9), vaccine-VSVRI), they had 98.6% identity, while other strains had 100% identity. The results of this study's mutation research showed that fowlpox-AN1, fowlpox-AN4, and fowlpox-AN5 had acquired novel mutations; fowlpox-AN1 had R201G and T204A; fowlpox-AN4 and fowlpox-AN5 had L141F and H157P. Further research is required to determine the effectiveness of the current vaccine in order to develop a new vaccine.

ABSTRACT: The present study aims to validate the Gompertz model to predict the growth performance of chicken crosses according to growth curve parameters of the parental lines and the estimated heterosis for each curve parameter. A total of 252 one-day-old chicks of both sexes belonging to 6 genotypes, including Ross 308, Sassò (SA), Bionda Piemontese (BP), and Robusta Maculata (RM), and the crosses between these local breeds and SA (BP × SA and RM × SA) were randomly allocated in 18 pens (3 pens/genotype) in mixed-sex groups (14 animals/pen; 7 females and 7 males). The individual body weight (BW) of all birds was recorded once a week from hatching until slaughtering (81 d for Ross 308; 112 d for SA, 140 d for the other genotypes). We drew up our final dataset with 240 birds (40 birds/genotype; 20 females and 20 males). The growth curve of each genotype was described using the Gompertz model, and the heterosis for each growth curve parameter was calculated as the difference between F1 crosses and the average of parental breeds. The predicted growth curve parameters were evaluated by cross-validation. The Gompertz model accurately estimated the growth curves of all the genotypes (R2 > 0.90). Heterosis was significant for almost all growth curve parameters in both crosses (P < 0.05). Heterosis ranged from −13.0 to +11.5%, depending on parameters, but varied slightly between the crossbreeds (BP × SA and RM × SA). The predicted values of adult BW, weight at the inflection point, and maximum growth rate were overestimated for BP × SA and underestimated for RM × SA, with a mean error between observed and predicted values

ABSTRACT: The awareness of poultry production safety is constantly increasing. The safety of poultry production is defined as biosecurity and the health status of birds. Hence the constant pursuit of developing new strategies in this area is necessary. Biosecurity is an element of good production practices that ensures adequate hygiene and maintaining the health status of poultry production. Poultry production is the world leader among all livestock species. Producers face many challenges during rearing, which depend on the utility type, the direction of use, and consumer requirements. For many years, the aim was to increase production results. Increasing attention is paid to the quality of the raw material and its safety. Therefore, it is crucial to ensure hygiene status during production. It can affect the immune system's functioning and birds' health status. Feed, water, and environmental conditions, including light, gases, dust, and temperature, play an essential role in poultry production. This review aims to look for stimulators and modulators of the poultry immune system while affecting the biosecurity of poultry production. Such challenges in current research by scientists aim to respond to the challenges posed as part of the One Health concept. The reviewed issues are a massive potential for an innovative approach to poultry production and related risks as part of the interaction of the animal-human ecosystem.

ABSTRACT: In ovo corticosterone (CORT) exposure reportedly reduces growth and alters body composition traits in meat-type chickens. However, the mechanisms governing alterations in growth and body composition remain unclear but could involve myogenic stem cell commitment, and/or the presence of yolk steroid hormones. This study investigated whether in ovo CORT exposure influenced yolk steroid hormone content, as well as embryonic myogenic development in meat-type chickens. Fertile eggs were randomly divided at embryonic day (ED) 11 and administered either a control (CON; 100 µL of 10 mM PBS) or CORT solution (100 µL of 10 mM PBS containing 1 µg CORT) into the chorioallantoic membrane. Yolk samples were collected at ED 0 and ED 5. At ED 15 and hatch, embryos were humanely killed, and yolk and breast muscle (BM) samples were collected. The relative abundance of 15 steroid hormones, along with total lipid content was measured in yolk samples collected at ED 0, ED 5, ED 15, and ED 21. Muscle fiber number, cross-sectional area, and fascicle area occupied by muscle fibers were measured in BM samples collected at hatch. Relative expression of MyoD, MyoG, Pax7, PPARγ, and CEBP/β, and the sex steroid receptors were measured in BM samples collected at hatch. The administration of CORT had a limited effect on yolk steroid hormones. In ovo CORT significantly reduced fascicle area occupied by muscle fibers and CEBP/β expression was increased in CORT exposed birds at hatch. In addition, the quantity of yolk lipid was significantly reduced in CORT-treated birds. In conclusion, in ovo exposure to CORT does not appear to influence early muscle development through yolk steroid hormones in embryonic meat-type chickens however, the results provide a comprehensive analysis of the composition of yolk steroid hormones in ovo at different developmental time points. The findings may suggest increased mesenchymal stem cell commitment to the adipogenic lineage during differentiation and requires further investigation.

ABSTRACT: Molecular characterization of avian pathogenic Escherichia coli (APEC) is challenging due to the complex nature of its associated disease, colibacillosis, in poultry. Numerous efforts have been made toward defining APEC, and it is becoming clear that certain clonal backgrounds are predictive of an avian E. coli isolate's virulence potential. Thus, APEC can be further differentiated as high-risk APEC based upon their clonal background's virulence potential. However, less clear is the degree of overlap between clinical isolates of differing bird type, and between clinical and gastrointestinal isolates. This study aimed to determine genomic similarities and differences between such populations, comparing commercial broiler vs. turkey isolates, and clinical vs. gastrointestinal isolates. Differences were observed in Clermont phylogenetic groups between isolate populations, with B2 as the dominant group in turkey clinical isolates and G as the dominant group in broiler clinical isolates. Nearly all clinical isolates were classified as APEC using a traditional gene-based typing scheme, whereas 53.4% and 44.1% of broiler and turkey gastrointestinal isolates were classified as APEC, respectively. High-risk APEC were identified among 31.0% and 46.9% of broiler and turkey clinical isolates, compared with 5.7% and 2.9% of broiler and turkey gastrointestinal isolates. As found in previous studies, no specific known virulence or fitness gene sets were identified which universally differentiate between clinical and gastrointestinal isolates. This study further demonstrates the utility of a hybrid APEC typing approach, considering both plasmid content and clonal background, for the identification of dominant and highly virulent APEC clones in poultry production.

ABSTRACT: Highly pathogenic avian influenza (HPAI) is a serious viral infection that causes massive economic losses in poultry. The current study investigated the HPAI virus prevalence in commercial broiler chicken flocks from 2019 to 2022. Organ samples, including trachea, cecal tonsils, spleen, brain, as well as tracheal and cloacal swabs, were harvested from 111 problematic broiler chicken flocks that suffered from variable mortalities accompanied with respiratory signs (103 H5-vaccinated and 8 nonvaccinated flocks) in Egypt during the observation duration. Molecular tools were used to analyze the samples, including real-time reverse transcription-polymerase chain reaction (rRT-PCR) and sequence analysis of some PCR positive strains. The results indicated that 24 flocks were positive for HPAI H5N8, representing 21.6%, with 22.3% (23/103) prevalence and 12.5% (1/8) detection in vaccinated and nonvaccinated flocks, respectively, and they were almost detected in the autumn and winter seasons. Phylogenetic evaluation of the hemagglutinin (HA) gene showed that the 6 Egyptian strains were clustered in clade 2.3.4.4b and allocated into 2 groups (I and II). The samples recovered in 2019 were clustered in new subgroup A, and samples recovered in 2020 to 2022 were clustered in new subgroup B with 10 nucleotide mutations (R72S, A83D, T140A). In conclusion, HPAI H5N8 is a serious threat even in vaccinated birds; to control such problems, periodic molecular monitoring with vaccine efficacy evaluation and the use of preventive strategies are recommended.

ABSTRACT: Many pathogens that cause chronic diseases in birds use the respiratory tract as a primary route of infection, and respiratory disorders are the main leading source of financial losses in the poultry business. Respiratory infections are a serious problem facing the poultry sector, causing severe economic losses. Avian influenza virus, Newcastle disease virus, infectious bronchitis virus, and avian pneumovirus are particularly serious viral respiratory pathogens. Mycoplasma gallisepticum, Staphylococcus, Bordetella avium, Pasteurella multocida, Riemerella anatipestifer, Chlamydophila psittaci, and Escherichia coli have been identified as the most serious bacterial respiratory pathogens in poultry. This review gives an updated summary, incorporating the latest data, about the evidence for the circulation of widespread, economically important poultry respiratory pathogens, with special reference to possible methods for the control and prevention of these pathogens.

ABSTRACT: Campylobacter jejuni (C. jejuni) is the most common food-borne pathogen that causes human gastroenteritis in the United States. Consumption of contaminated poultry products is considered as the major source of human Campylobacter infection. An effective vaccine would be a promising alternative to antibiotic supplements to curb C. jejuni colonization in poultry gastrointestinal (GI) tract. However, the genetic diversity among the C. jejuni isolates makes vaccine production more challenging. Despite many attempts, an effective Campylobacter vaccine is not yet available. This study aimed to identify suitable candidates to develop a subunit vaccine against C. jejuni, which could reduce colonization in the GI tract of the poultry. In the current study, 4 C. jejuni strains were isolated from retail chicken meat and poultry litter samples and their genomes were sequenced utilizing next-generation sequencing technology. The genomic sequences of C. jejuni strains were screened to identify potential antigens utilizing the reverse vaccinology approach. In silico genome analysis predicted 3 conserved potential vaccine candidates (phospholipase A [PldA], TonB dependent vitamin B12 transporter [BtuB], and cytolethal distending toxin subunit B [CdtB]) suitable for the development of a vaccine. Furthermore, the expression of predicted genes during host-pathogen interaction was analyzed by an infection study using an avian macrophage-like immortalized cell line (HD11). The HD11 was infected with C. jejuni strains, and the RT-qPCR assay was performed to determine the expression of the predicted genes. The expression difference was analyzed using ΔΔCt methods. The results indicate that all 3 predicted genes, PldA, BtuB, and CdtB, were upregulated in 4 tested C. jejuni strains irrespective of their sources of isolation. In conclusion, in silico prediction and gene expression analysis during host-pathogen interactions identified 3 potential vaccine candidates for C. jejuni.