Extraction and characterization of valuable compounds from chicken sternal cartilage: Type II collagen and chondroitin sulfate.

Type II collagen (Col II) and chondroitin sulfate (CS) are the main macromolecules in the extracellular matrix. This study investigated the characteristics of Col II and CS obtained from chicken sternal cartilage (CSC) via enzymatic hydrolysis for various treatment times. For Col II and CS, the highest efficiency of enzymatic hydrolysis was achieved after 24 and 6 h of treatment, respectively. The average molecular weights were α1 chain-130 kDa, ß chain-270 kDa for Col II, and 80.27 kDa for CS. Fourier transform infrared spectroscopy revealed that the Col II samples maintained their triple-helical structure and that the predominant type of CS was chondroitin-4-sulfate. Scanning electron microscopy revealed that the Col II and CS samples possessed fibrillar and clustered structures, respectively. This study suggests that collagen and CS obtained from CSC can be used as promising molecules for application in food and pharmaceutical industries.

Nuclei Isolation from Ocular Tissues of the Embryonic Chicken for Single-Nucleus Profiling.

The generation of quality data from a single-nucleus profiling experiment requires nuclei to be isolated from tissues in a gentle and efficient manner. Nuclei isolation must be carefully optimized across tissue types to preserve nuclear architecture, prevent nucleic acid degradation, and remove unwanted contaminants. Here, we present an optimized workflow for generating a single-nucleus suspension from ocular tissues of the embryonic chicken that is compatible with various downstream workflows. The described protocol enables the rapid isolation of a high yield of aggregate-free nuclei from the embryonic chicken eye without compromising nucleic acid integrity, and the nuclei suspension is compatible with single-nucleus RNA and ATAC sequencing. We detail several stopping points, either via cryopreservation or fixation, to enhance workflow adaptability. Further, we provide a guide through multiple QC points and demonstrate proof-of-principle using two commercially available kits. Finally, we demonstrate that existing in silico genotyping methods can be adopted to computationally derive biological replicates from a single pool of chicken nuclei, greatly reducing the cost of biological replication and allowing researchers to consider sex as a variable during analysis. Together, this tutorial represents a cost-effective, simple, and effective approach to single-nucleus profiling of embryonic chicken eye tissues and is likely to be easily modified to be compatible with similar tissue types.

Antioxidant capacity of fermented corn gluten meal in broiler chickens: a solid-state approach with mixed microbial fermentation.

Fermentation of feed with probiotic and biofunctional properties has gained global attention for its potential to enhance digestive absorption and improve overall functional quality. This study investigates the antioxidant capacity and expression of antioxidant-related genes in broiler chickens fed with fermented corn gluten meal (FCGM) containing mixed microbial cultures. Seventy-two male Yellow-Feathered broiler chickens were randomly assigned to 2 groups, each consisting of 3 replicates, and were fed experimental diets containing either corn gluten meal or FCGM for 42 d. The antioxidant capacity of FCGM was assessed in vivo. Chickens fed with FCGM exhibited significant increases in serum glutathione concentration, as well as enhanced activities of total superoxide dismutase, glutathione peroxidase, and catalase (CAT) in their serum. Similar trends were observed in the liver, specifically in the activities of glutathione peroxidase and CAT. Additionally, the expression levels of key antioxidant-related genes in the liver, such as glutathione synthase, superoxide dismutase 1, superoxide dismutase 2, CAT, and glutathione peroxidase 1, were examined. The results indicated that FCGM significantly enhanced antioxidant capacity in broiler chickens. This study highlights the potential benefits of utilizing solid-state fermentation with mixed microbial cultures to improve the antioxidant properties of corn gluten meal, thereby contributing to the overall health and well-being of broiler chickens.

The influence of Quercetin on behavior, performance and splenic immunity in broiler chickens.

Quercetin (QRT), a potent flavonoid, holds immense mechanistic potential in enhancing various aspects of broiler chicken physiological status. This comprehensive study explores the profound еffеcts of QRT on behavior, productive performance, and immune functions, unraveling the underlying mechanisms behind its efficacy. Four hundred, one-day-old Cobb 500 chicks were placed randomly into 4 supplementation groups (100 birds /group and five replicates) and provided diets enriched with varying concentrations of QRT (0, 200, 400, and 600 ppm) for six weeks. Visual scanning revealed significant (P > 0.05) improvements in feeding and body care behaviors, accompanied by reduced instances of idleness and walking in the QRT-supplemented groups. Moreover, QRT supplementation exerted a substantial (P > 0.05) positive influence on weight gain, feed intake and the final body weight of the broilers. In-depth evaluation of immune parameters, QRT supplementation elicited significant (P > 0.05) enhancements in immune functions, including improved spleen, thymus, and bursa indices, enhanced secretion of immunoglobulin M (IgM) and immunoglobulin A (IgA), and stimulated humoral immunity against sheep red blood cells (SRBCs). Furthermore, QRT displays potent antioxidant properties, as showed by diminished splenic malondialdehyde levels and augmented activity of antioxidative stress enzymes. Remarkably, QRT supplementation elicited dose-dependent upregulation (P < 0.001) of key immune-related genes, such as intеrlеukin-4 (IL-4), interferon-γ (INF-γ), Toll-like receptor 2 (TLR2), and tumor necrosis factor-α (TNF-α) in the splenic tissue. Collectively, these mechanistic insights underscore the profound impact of QRT as a functional feed additive, fostering enhanced behavior, performance, and immune function in broiler chickens, while delivering robust antioxidant fortification.

Geographical Variation of Antimicrobial Resistance of Salmonella in Japanese Chicken.

Chicken is a potent source of Salmonella infection in humans. Occasionally, patients with severe Salmonella enteritis require antimicrobial therapy. Antimicrobials are used to prevent and treat bacterial infections in broiler and breeder farms. Herein, we investigated the prevalence and antimicrobial resistance of Salmonella in 337 vacuum-packed chicken breast products manufactured in Japan between June and December 2021. Salmonella was isolated from 287 samples (85.2%). Among the products from Eastern Japan, the lowest Salmonella prevalence was observed in those processed in September (65.6%), which was significantly (p < 0.05) lower than that in November or December. Among the products from Western Japan, the lowest Salmonella prevalence was observed in those processed in August (61.9%), which was significantly (p < 0.05) lower than that in June, November, and December. The most frequent serovar was Salmonella Schwarzengrund (223 isolates), followed by S. Infantis (53 isolates), S. Manhattan (9 isolates), and S. Enteritidis (1 isolate). High rates of antimicrobial resistance were observed for streptomycin (64.5%), kanamycin (50.2%), tetracycline (65.2%), nalidixic acid (11.5%), and trimethoprim (35.9%). Resistance rates against these five antimicrobials in S. Schwarzengrund isolates were markedly higher in the isolates from Western Japan than in those from Eastern Japan. All 287 Salmonella isolates were susceptible to ciprofloxacin which belongs to fluoroquinolones and cefotaxime which belongs to third-generation cephalosporins. Salmonella prevalence in chicken products in Japan was found to be extremely high; therefore, chicken meat should be thoroughly heated before consumption. In Japan, fluoroquinolones and third-generation cephalosporins are recommended as the first- and second-choice antimicrobials for patients with severe Salmonella enteritis, respectively. The results of this study show that administering fluoroquinolones or third-generation cephalosporins is an effective option for patients with Salmonella enteritis caused by consuming chicken meat, and efficient strategies for Salmonella management on broiler farms and chicken-processing plants need to be developed.

The anti-inflammatory effect of arsenic trioxide effectively mitigates the pathogenic process in local chickens with avian leukosis.

Arsenic trioxide (ATO) is a classic first-line treatment for acute promyelocytic leukemia (APL). An increasing number of studies regarding the use of ATO in tumor treatment have shown consistently remarkable results. In this study, subgroup J avian leukosis virus (ALV-J) was used as a model virus, and different doses of ATO were used to treat ALV-J-positive chickens. Sexually mature green-shelled laying hens from the same ALV-J-positive offspring were grouped and treated with one of 3 different doses of ATO. The anti-inflammatory effects of different doses of ATO in ALV-J-positive chickens and their mechanisms were investigated by analyzing levels of inflammatory cytokines, antioxidant parameters and apoptosis-related genes. The results showed that ATO administration mitigated ALV-induced lymphoid leukosis in the liver. ATO inhibited the activation of the TLR4/MyD88/NF-κB signaling pathway and downregulated the expression levels of the inflammatory cytokines IL-1ß, IL-6 and TNF-α. The SOD and GSH-Px activities were also increased, and the MDA content was decreased in the serum of ALV-J-positive chickens treated with different doses of ATO, so the antioxidant capacity of ALV-J-positive chickens was improved. The mRNA expression levels of p53, p21 and Bcl-2 in the livers of ALV-J-positive chickens treated with different doses of ATO were significantly downregulated, which induced the apoptosis of tumor cells and slowed the inflammatory response. The combined analysis revealed that the therapeutic effect of 2 mg/kg/dose ATO was superior to that of the other 2 treatments (0.5 and 1 mg/kg/dose ATO). In conclusion, the anti-inflammatory effect of ATO can effectively alleviate the ALV-J pathogenic process. ALV-J serves as a model virus for antiviral tumor research, while ATO provides references for the treatment of such tumors.

Effect of egg incubator temperature on sex differentiation in Korat chickens.

The effect of incubator temperature on sex differentiation in Korat chickens was investigated. The experiments were divided into two sets: temperature applied throughout the entire incubation period and temperature applied during certain periods (days 3-6 of incubation) by either increasing above the standard or decreasing below the standard temperature. In each experiment, 300 Korat chicken eggs were separated into three groups of 5 repetitions, with 20 eggs in each group. This was done using a completely randomized design for each experiment: a group using a temperature below the standard for incubation (36.0 °C), a group using the standard incubation temperature (37.7 °C), and a group using a temperature above the standard for incubation (38.0 °C). W chromosomes were detected at hatch; histology examined reproductive structures after 35 days. Increasing the temperature to 38.0 °C throughout the entire incubation period resulted in no significant difference in hatching rates compared to the standard temperature (P > 0.05). Raising the temperature to 38.0 °C throughout the entire incubation and during certain periods resulted in changes in the reproductive structure of chickens, leading to a mismatch between chromosomal and gonadal sex, observed at 9.7% and 5.9% of individuals with W chromosomes possessed testes, indicating a mismatch between chromosomal and gonadal sex. However, decreasing the temperature to 36.0 °C throughout the incubation period resulted in lower hatching rates compared to the standard temperature (P < 0.05). Incubating eggs at 36.0 °C for specific periods resulted in 19.4% of genetic males developing ovaries instead of testes. The presence of ovaries in individuals without W chromosomes indicated this mismatch. The results of this study provide evidence that temperature plays a role in sex differentiation in Korat chickens, as demonstrated by the detection of W chromosomes and histological studies of testes and ovaries. Moreover, this study presents the first evidence in broilers that temperature can affect sex differentiation.

Detection of Staphylococcal Enterotoxins A and E and Methicillin Resistance in Staphylococcus aureus Strains From Moroccan Broiler Chicken Meat.

Foodborne epidemics have become a serious public health emergency worldwide. Foods of animal origin, in particular chicken meat, are considered to be potential vectors of pathogenic bacteria, particularly Staphylococcus aureus. This bacterium can be resistant in the form of methicillin-resistant S. aureus (MRSA) or produce enterotoxins leading to food poisoning when ingested. This study is aimed at exploring the virulence genes in S. aureus responsible for producing enterotoxins (staphylococcal enterotoxin [SE] A [sea] and SE E [see]) and determining the prevalence of MRSA in raw broiler meat in the Casa-Rabat region in Morocco. A quantitative (q) PCR (qPCR) assay, using specific primers for S. aureus (nuc) confirmation and detection of enterotoxin genes (sea and see), as well as the methicillin-resistant gene (mecA), was employed. Our findings indicated that all tested strains were positively identified as S. aureus. Among them, one isolate (1/54) tested positive for the see gene (1.85%), while none carried the sea gene. Furthermore, the mecA gene, indicative of MRSA, was present in 12/54 of the isolates (22.22%). The potential presence of MRSA in Moroccan poultry meat underscores a public health risk. Thus, stringent measures are imperative to curtail the contamination and proliferation of this bacterium during the slaughtering process, underscoring the importance of continuing research into the prevalence of MRSA colonization among poultry slaughterhouse personnel.

Selection criteria and husbandry practices of indigenous chicken producers in Northwest Ethiopia.

This study was conducted to identify the selection criteria and husbandry practices of chicken producers in different agro-ecological zones of Northwest Ethiopia as input for designing a breeding program. The study employed a purposive selection of districts and peasant associations with high indigenous chicken potential. The study areas were stratified based on the major agro-ecologies (highland, midland, and lowland). A total of 360 households were included in the study, and data on chicken breeding practices, selection criteria, and reproductive performance were collected and analyzed using SPSS software. In all agro-ecologies, egg production was prioritized by chicken owners when choosing female chickens. For male chickens, plumage color (index = 0.27), appearance (index = 0.24), and growth rate (index = 0.23) were the main selection factors. Farmers kept chickens primarily to generate cash through the sale of eggs and live animals (male chickens). There was a significant difference (p < 0.01) among agro-ecologies in nutritional management and housing of chickens. Chicken flock composition showed a highly significant difference (p < 0.001) among agro-ecologies, except layers. Most of the farmers had their own cock born in the flock. Chicken owners found in all agro-ecologies were practicing culling unwanted chickens. All the reproductive performance traits have shown a highly significant (p < 0.001) difference among agro-ecologies. A relatively higher inbreeding coefficient (0.18) was obtained in the highland agro-ecology compared to midland (0.16) and lowland (0.12). The study highlighted the importance of designing breeding programs that align with farmers' production objectives and trait preferences based on specific agro-ecologies for sustainable increases in chicken productivity.

Antibacterial Activity and Mechanism of Lauric Acid Against Staphylococcus aureus and Its Application in Infectious Cooked Chicken.

Staphylococcus aureus contamination and prevention has always been a major concern for food industry. This work investigated the antibacterial activity and mechanisms of lauric acid (LA) against S. aureus. Results revealed 156 µg/mL was the minimum inhibitory concentration (MIC) for LA and it retarded growth rate of S. aureus. The inhibitory effect was enhanced with LA concentration. After being treated with 2 MIC LA for 24 h, the number of S. aureus decreased by 3.56 log colony-forming unit (CFU)/mL. Scanning electron microscopy profiling revealed that LA resulted in altered morphology of S. aureus cells. In addition, propidium iodide staining of flow cytometry suggested that LA treatment disrupted the cell membrane integrity. Changes in 8-anilino-1-naphthalenesulfonic acid fluorescence indicated a depolarization change in cell membrane fluidity. For practical applications, LA also displayed an antimicrobial potential in cooked chicken food model system, with 1.25-5 g/L of LA prolonging shelf life by 2 days at 4°C. Moreover, it had no adverse effect on pH values, color in cooked chicken meat, and even reduced lipid oxidation. To sum up, LA has great antimicrobial properties and is a candidate preservative for cooked meat food.

Determination and evaluation of canthaxanthin and ß-apo-8'-carotenoid ethyl ester in chicken eggs and meat in Tianjin.

Canthaxanthin and ß-apo-8'-carotenoid ethyl ester are widely used as feed additives in poultry feed for enhancing the color of poultry products. The excessive intake of the two colorants can cause health damage. According to the European Food Safety Authority (EFSA), the acceptable daily intake (ADI) of canthaxanthin and ß-apo-8'-carotenoid ethyl ester are 0.03 mg/kg·bw and 0.015 mg/kg·bw, respectively. Ultra-high-performance liquid chromatography-diode array detector (UPLC-DAD) was used to determine two colorants in chicken eggs and meat. A PRiME HLB solid-phase extraction cartridge was used to extract and clean-up the sample. BEH C18 column was used as the separation column, with water containing 0.1% formic acid and acetonitrile as the mobile phase. The limit of detection (LOD) was 0.05 mg/kg, and the limit of quantification (LOQ) was 0.1 mg/kg. The recoveries were between 90% and 104%. The daily intake of two colorants in chicken eggs and meat was evaluated based on the detection data, food consumption data and weight data of the population. The mean estimated daily intake (EDI) values of canthaxanthin through chicken eggs and meat were 1.09 µg/(kg·bw·d) and 0.013 µg/(kg·bw·d), respectively. The mean EDI value of ß-apo-8'-carotenoid ethyl ester through eggs was 0.44 µg/(kg·bw·d). The results showed that eggs were the main contributor to the daily intake of two colorants. The mean hazard quotients (HQ) values of two colorants through chicken eggs and meat was within a safe range.

Social Environment Alters the Duration of Rapid Yolk Deposition in Eggs of Domestic Hens.

AbstractThe social environment can drive female birds to alter their investment in reproduction in the form of greater incubation behavior, more parental care, and greater allocation of physiological mediators to yolks. However, less is known about how social variables impact the speed at which females grow ovarian follicles in preparation for ovulation. We hypothesized that the social environment would influence how long ovarian follicles remain in rapid yolk deposition before reaching the size necessary for ovulation. For 8 d, we tested the effects of three types of social interactions: no social engagement (control), engagement with the same four females (social group 1), or engagement with the same four females plus six randomly selected roosters (social group 2). Starting on day 5 of engagement, we collected eggs and measured egg and yolk masses and yolk diameters. Then we stained the yolks with potassium dichromate to quantify the number of days the ovarian follicle spent accumulating yolk. We compared the results of the treatment groups with those of the control hens that were kept in individual laying cages throughout the study. The number of eggs laid, the yolk mass, and the yolk diameter did not differ among any of the three groups, but hens exposed to both females and males produced yolks with significantly more rings than hens in the other groups. Thus, the presence of males appeared to lengthen the time it took for ovarian follicles to reach the size needed for ovulation but did not result in larger or heavier yolks.

Visual Navigation of Caged Chicken Coop Inspection Robot Based on Road Features.

The speed and accuracy of navigation road extraction and driving stability affect the inspection accuracy of cage chicken coop inspection robots. In this paper, a new grayscale factor (4B-3R-2G) was proposed to achieve fast and accurate road extraction, and a navigation line fitting algorithm based on the road boundary features was proposed to improve the stability of the algorithm. The proposed grayscale factor achieved 92.918% segmentation accuracy, and the speed was six times faster than the deep learning model. The experimental results showed that at the speed of 0.348 m/s, the maximum deviation of the visual navigation was 4 cm, the average deviation was 1.561 cm, the maximum acceleration was 1.122 m/s2, and the average acceleration was 0.292 m/s2, with the detection number and accuracy increased by 21.125% and 1.228%, respectively. Compared with inertial navigation, visual navigation can significantly improve the navigation accuracy and stability of the inspection robot and lead to better inspection effects. The visual navigation system proposed in this paper has better driving stability, higher inspection efficiency, better inspection effect, and lower operating costs, which is of great significance to promote the automation process of large-scale cage chicken breeding and realize rapid and accurate monitoring.

Evaluating potential of H'mong chicken bone marrow-derived mesenchymal stem cells at different ages for primordial germ cells' feeder layer.

Primordial germ cells (PGCs) have potential applications in genetic conservation, vaccination, tissue repair therapies, and genetic research. Chicken bone marrow-derived mesenchymal stem cells (cbMSCs) is a good candidate for co-culture with PGCs. However, there is no consensus on the optimal age of donors. In this study, we aimed to compare specific parameters of H'Mong cbMSCs obtained from day 14th and 19th embryos, and day 3rd newborns. Isolated cbMSCs showed characteristics of MSCs. Cells had fibroblast-like morphology, plastic-adherent, expressed specific markers of MSCs and multilineage differentiation potential. The growth rate of cells from day 19th embryos was higher than from other ages. Moreover, cells expressed markers of pluripotency such as Nanog, PouV, Sox2, CVH, DAZL, and KIT, known for their role in maintaining stem cell self-renewal and pluripotency. As feeder cells, cbMSCs from three different ages promoted proliferation of H'Mong PGCs during co-culture. These results suggested that cbMSCs from different ages can be used for co-culture H'Mong PGCs which were further used for genetic preservation of H'Mong chicken or gene editing research.

Impact of long-term feeding a high level of Spirulina combined with enzymes on growth performance, carcass traits and meat quality in broiler chickens.

This study evaluates the effect of prolonged feeding with a high inclusion level of Spirulina, combined with peptidases, on broiler chicken's growth performance, digesta viscosity, carcass attributes and meat quality. The experiment involved 120 male broilers divided into 40 battery brooders, each housing 3 birds. Post 7-day acclimatisation with a corn and soybean-based diet, the birds were provided with one of four diets: a corn and soybean meal-based diet (CON), a mix incorporating 15% Spirulina (SP), a Spirulina-rich mix supplemented with 0.025% of commercial VemoZyme® P (SPV), or a Spirulina-rich mix supplemented with 0.10% of porcine pancreatin (SPP). The CON group had higher body weight and weight gain (p < 0.001) and a lower feed conversion ratio (p < 0.001) from day 7-21, compared to the Spirulina-fed groups. Spirulina-fed chickens significantly increased ileum viscosity (p < 0.05). Spirulina also elevated the weight (p < 0.05) of the duodenum and the length (p < 0.001) of the entire gastrointestinal tract compared to CON. Breast and thigh muscles from Spirulina-fed broilers displayed higher values of yellowness (b*) (p < 0.001), pigments (p < 0.05), and n-3 PUFA (p < 0.01), while n-6/n-3 ratio (p < 0.001) and α-tocopherol (p < 0.001) decreased relative to the CON. In conclusion, the introduction of a high level of Spirulina into broiler diets for an extended duration, has the potential to diminish birds' growth performance, possibly due to increased digesta viscosity. However, it does enhance the nutritional quality of the meat.

Increasing concentrations of dietary threonine, tryptophan, and glycine improve growth performance and intestinal health with decreasing stress responses in broiler chickens raised under multiple stress conditions.

The current study aimed to compare the effects of increasing concentrations of dietary threonine (Thr), tryptophan (Trp), and glycine (Gly) on growth performance, stress biomarkers, and intestinal function in broiler chickens under multiple stress conditions. Five hundred sixty broiler chickens at 21 d old were randomly allotted to 5 treatments with 8 replicates. Birds in a positive control (PC) treatment were raised under low stock density (16.9 birds/m2 per cage) with recommended environmental conditions, whereas birds in 4 treatments were subjected to multiple stress conditions: a cyclic heat stress of 30 ± 0.3 °C for 10 h and 23 ± 0.2 °C for 14 h per day with high stock density (25.3 birds/m2 per cage). A basal diet was assigned to both PC and negative control (NC) treatments. Three additional diets were individually formulated to contain double concentrations of digestible Thr, Trp, or Gly + Ser compared with their concentrations in the basal diet. The experiment lasted for 14 d. Results showed that NC treatment had less growth performance (P < 0.001), jejunal goblet cell counts (P = 0.018), and trans-epithelial electrical resistance (TEER; P < 0.001), but greater (P = 0.026) feather corticosterone (CORT) concentrations than PC treatment. Thr treatment showed the least (P < 0.001) feed conversion ratio (FCR) among treatments under multiple stress conditions. Thr, Trp, and Gly treatments had less (P = 0.026) feather CORT concentrations, but had greater (P < 0.001) TEER than NC treatment. In conclusion, increasing concentrations of dietary Thr, Trp, or Gly improve the growth performance and intestinal health in broiler chickens with decreasing stress response under multiple stress conditions.

l-Arginine and l-lysine improve the emulsifying and dissolution properties of pale, soft, exudative-like chicken myofibrillar proteins by modifying their conformations.

Herein, we investigated the effect and potential mechanisms of l-arginine (Arg) and l-lysine (Lys) on the emulsifying and dissolution properties of pale, soft, exudative (PSE)-like chicken myofibrillar proteins (MPs). The findings revealed that Arg/Lys effectively enhanced the emulsion activity and emulsion stability indexes of PSE-like MPs, resulting in smaller and more uniform PSE-like MP-soybean oil emulsions. Arg/Lys increased the solubility, absolute potential, hydrophobicity, fluorescence intensity, and ß-sheet content and decreased the turbidity, particle size, and ß-turn and random coil content of PSE-like MPs. Additionally, Arg/Lys did not significantly affect the Schiff base, carbonyl group, and total sulfhydryl contents, but caused a red shift of the band near 299 nm, indicating conformational rather than primary structural changes. Altogether, these findings indicate that Arg/Lys improves the emulsifying and dissolution performances of PSE-like MPs by adjusting conformation and contributes to a better understanding of how Arg/Lys enhances the physicochemical properties of PSE-like sausages.

Pecking up Optimism: Learning Opportunities Improve Mood for Sanctuary-Living Cornish Cross Chickens.

Understanding what influences mood (optimism/pessimism) is crucial in determining whether environments are conducive to positive welfare. This study explores the impact of learning opportunities on mood in Cornish Cross chickens (also known as "broiler chickens"), of which over nine billion individuals are raised annually for meat in the United States. We predicted that access to learning opportunities promotes optimism in these chickens. We conducted yoked-control design experimental trials and two judgment bias tests (baseline and post-experimental) with eight adult sanctuary-living hens. There were significant post-experimental between-group differences in mood, with those who had access to learning opportunities experiencing greater optimism than those who did not. These results suggest that learning and the ability to control access to rewards may contribute positively to the welfare of Cornish Cross chickens.

Machine learning to attribute the source of Campylobacter infections in the United States: A retrospective analysis of national surveillance data.

OBJECTIVES: Integrating pathogen genomic surveillance with bioinformatics can enhance public health responses by identifying risk and guiding interventions. This study focusses on the two predominant Campylobacter species, which are commonly found in the gut of birds and mammals and often infect humans via contaminated food. Rising incidence and antimicrobial resistance (AMR) are a global concern, and there is an urgent need to quantify the main routes to human infection. METHODS: During routine US national surveillance (2009-2019), 8856 Campylobacter genomes from human infections and 16,703 from possible sources were sequenced. Using machine learning and probabilistic models, we target genetic variation associated with host adaptation to attribute the source of human infections and estimate the importance of different disease reservoirs. RESULTS: Poultry was identified as the primary source of human infections, responsible for an estimated 68% of cases, followed by cattle (28%), and only a small contribution from wild birds (3%) and pork sources (1%). There was also evidence of an increase in multidrug resistance, particularly among isolates attributed to chickens. CONCLUSIONS: National surveillance and source attribution can guide policy, and our study suggests that interventions targeting poultry will yield the greatest reductions in campylobacteriosis and spread of AMR in the US. DATA AVAILABILITY: All sequence reads were uploaded and shared on NCBI's Sequence Read Archive (SRA) associated with BioProjects; PRJNA239251 (CDC / PulseNet surveillance), PRJNA287430 (FSIS surveillance), PRJNA292668 & PRJNA292664 (NARMS) and PRJNA258022 (FDA surveillance). Publicly available genomes, including reference genomes and isolates sampled worldwide from wild birds are associated with BioProject accessions: PRJNA176480, PRJNA177352, PRJNA342755, PRJNA345429, PRJNA312235, PRJNA415188, PRJNA524300, PRJNA528879, PRJNA529798, PRJNA575343, PRJNA524315 and PRJNA689604. Contiguous assemblies of all genome sequences compared are available at Mendeley data (assembled C. coli genomes doi: 10.17632/gxswjvxyh3.1; assembled C. jejuni genomes doi: 10.17632/6ngsz3dtbd.1) and individual project and accession numbers can be found in Supplementary tables S1 and S2, which also includes pubMLST identifiers for assembled genomes. Figshare (10.6084/m9.figshare.20279928). Interactive phylogenies are hosted on microreact separately for C. jejuni (https://microreact.org/project/pascoe-us-cjejuni) and C. coli (https://microreact.org/project/pascoe-us-ccoli).

Decoding the duration of fertility of laying chicken through phenotypic and proteomic evaluation.

1. This study determined the effective indicators and proteins involved in long-duration fertility (DF) in chickens.2. Three lines of Chinese Xinhua chickens (900) were compared using seven phenotypic trait indicators, and the best was determined based on repeatability value. Subsequently, differential expression analysis, functional annotation and protein-protein interaction (PPI) network analyses were performed to investigate the pathways and hub proteins. Finally, qPCR analysis was conducted to validate the expression of identified hub proteins, and functional annotation with previously published genes was performed to explain how hub proteins work to maintain the trait.3. The study found that the number of fertilised eggs (FN) and maximum fertilised eggs (MCF) were the most repeatable among the seven indicators. It identified 231 differentially expressed proteins, with 144 being down-regulated and 87 being up-regulated. The differentially expressed proteins exhibited high clustering within various cellular compartments, including the cytosol and cytoplasm and GTP binding. Multiple pathways were identified, including tight and adherens junctions, TGF-beta signalling, autophagy-animal, regulation of actin cytoskeleton and the ribosome that may regulate the trait. Three hub proteins, KRAS, RPL5 (p < 0.001), and HSPA4 (p < 0.01), were significantly differentially expressed between high and low DF groups.4. This study identified FN and MCF as effective indicators for addressing DF. As it is a quantitative trait, KRAS, HSPA4, and RPL5 are potential hub proteins that work with other genes to maintain the trait.