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Heat stress results in significant economic losses to the poultry industry. Genetics plays an important role in chickens adapting to the warm environment. Physiological parameters such as hematochemical parameters change in response to heat stress in chickens. To explore the genetics of heat stress resilience in chickens, a genome-wide association study (GWAS) was conducted using Hy-Line Brown layer chicks subjected to either high ambient temperature or combined high temperature and Newcastle disease virus infection. Hematochemical parameters were measured during three treatment phases: acute heat stress, chronic heat stress, and chronic heat stress combined with NDV infection. Significant changes in blood parameters were recorded for 11 parameters (sodium (Na+, potassium (K+), ionized calcium (iCa2+), glucose (Glu), pH, carbon dioxide partial pressure (PCO2), oxygen partial pressure (PO2), total carbon dioxide (TCO2), bicarbonate (HCO3), base excess (BE), and oxygen saturation (sO2)) across the three treatments. The GWAS revealed 39 significant SNPs (p < 0.05) for seven parameters, located on Gallus gallus chromosomes (GGA) 1, 3, 4, 6, 11, and 12. The significant genomic regions were further investigated to examine if the genes within the regions were associated with the corresponding traits under heat stress. A candidate gene list including genes in the identified genomic regions that were also differentially expressed in chicken tissues under heat stress was generated. Understanding the correlation between genetic variants and resilience to heat stress is an important step towards improving heat tolerance in poultry.

Infectious bronchitis virus (IBV) induces severe economic losses in chicken farms due to the emergence of new variants leading to vaccine breaks. The studied IBV strains belong to Massachusetts (Mass), Canadian 4/91, and California (Cal) 1737 genotypes that are prevalent globally. This study was designed to compare the impact of these three IBV genotypes on primary and secondary lymphoid organs. For this purpose, one-week-old specific pathogen-free chickens were inoculated with Mass, Canadian 4/91, or Cal 1737 IBV variants, keeping a mock-infected control. We examined the IBV replication in primary and secondary lymphoid organs. The molecular, histopathological, and immunohistochemical examinations revealed significant differences in lesion scores and viral distribution in these immune organs. In addition, we observed B-cell depletion in the bursa of Fabricius and the spleen with a significant elevation of T cells in these organs. Further studies are required to determine the functional consequences of IBV replication in lymphoid organs.

Large-scale cell flow characterizes gastrulation in animal development. In amniote gastrulation, particularly in avian gastrula, a bilateral vortex-like counter-rotating cell flow, called 'polonaise movements', appears along the midline. Here, through experimental manipulations, we addressed relationships between the polonaise movements and morphogenesis of the primitive streak, the earliest midline structure in amniotes. Suppression of the Wnt/planar cell polarity (PCP) signaling pathway maintains the polonaise movements along a deformed primitive streak. Mitotic arrest leads to diminished extension and development of the primitive streak and maintains the early phase of the polonaise movements. Ectopically induced Vg1, an axis-inducing morphogen, generates the polonaise movements, aligned to the induced midline, but disturbs the stereotypical cell flow pattern at the authentic midline. Despite the altered cell flow, induction and extension of the primitive streak are preserved along both authentic and induced midlines. Finally, we show that ectopic axis-inducing morphogen, Vg1, is capable of initiating the polonaise movements without concomitant PS extension under mitotic arrest conditions. These results are consistent with a model wherein primitive streak morphogenesis is required for the maintenance of the polonaise movements, but the polonaise movements are not necessarily responsible for primitive streak morphogenesis. Our data describe a previously undefined relationship between the large-scale cell flow and midline morphogenesis in gastrulation.

Extensive antibiotic use in the poultry industry has given rise to concerns of the proliferation and potential zoonotic transmission of antimicrobial-resistant pathogens. To mitigate the extent of antibiotic dosing, probiotics have been proposed as an alternate means of enhancing chick immune function by boosting host defense peptide (HDP) production. This study measured chick immune response to in ovo supplementation of a commercial poultry probiotic when subsequently exposed to a mimicked viral threat using polyinosinic-polycytidylic acid (poly(I:C)). To assess systemic immune responses to these conditions, real-time PCR was conducted to measure changes in expression of five immune-related genes in the spleen: TLR-3, AvBD-2, IFN-a, IFN-b, and IL-6. The chicks that received only the probiotic treatment saw a downregulation of TLR-3 (p50.0013) and an upregulation of AvBD-2 (p50.0105). The expression of IL-6 tended towards downregulation (p50.06) with a potential interaction between the probiotic and poly(I:C) treatments (p50.0794). Upregulation of AvBD-2 indicates a higher basal output of the chick's innate immune system upon early exposure to probiotics. These results suggest that enhanced systemic immune response in chicks can be achieved through early application of probiotics and is occurring through immunomodulation pathways that have not been fully elucidated. [ABSTRACT FROM AUTHOR]

Summary: This study aimed to investigate the antioxidant and protease activities of red kiwifruit (RK), green kiwifruit (GRK), and gold kiwifruit (GOK) and determine the effects of various packaging methods on the quality of chicken breast injected with various kiwifruit types during storage. The physicochemical and textural properties of chicken breasts containing various kiwifruit types were evaluated. Chicken breasts were injected with brine solution containing 5% kiwifruit powder, and their product quality was measured every 3 days until day 9. GOK and RK addition to chicken breast delayed oxidation during storage. Adding GOK and GRK to chicken breast was found to increase tenderness. Modified‐atmosphere packaging (MAP) delayed microbial growth more effectively than over‐wrap packaging (OWP). These findings suggest that the combination of GOK and MAP potentially extends shelf‐life without deteriorating quality. [ABSTRACT FROM AUTHOR]

To compare the effects of propofol, ketamine–propofol and isoflurane, at similar anesthetic depth, on cardiopulmonary variables in unpremedictated chickens. Prospective, randomized, crossover experimental trial. A total of 10 male Leghorn domestic chickens, aged 3 months and body mass 1.4–2.0 kg. Birds were randomly assigned to each of three anesthetic protocols, 7 days apart: intravenous propofol, intravenous ketamine–propofol or isoflurane. Anesthesia was induced (indicated by loss of righting reflex and tracheal intubation) and maintained with propofol (10 mg kg–1 minute–1, then 1.1 mg kg–1 minute–1), ketamine–propofol (5 mg mL–1 ketamine and 5 mg mL–1 propofol combined; 10 mg kg–1 minute–1, then 1.1 mg kg–1 minute–1) or isoflurane [5% vaporizer setting initially, then end-tidal concentration (F e ′Iso) of 2%] for 65 minutes. Anesthesia was maintained at a similar anesthetic depth based upon positive or negative responses to toe pinch. Heart rate (HR), respiratory rate (f R), noninvasive arterial blood pressure and arterial blood gases were measured during anesthesia. Propofol or ketamine–propofol infusion rates and F e′ Iso required to prevent movement in response to a noxious stimulus and recovery times were recorded. Anesthesia induction dose was 9.0 ± 0.8 (mean ± SD) and 12.2 ± 0.3 mg kg–1 for propofol and ketamine–propofol, respectively. Propofol and ketamine–propofol infusion rates and F e′ Iso required to prevent movement in response to the noxious stimulus were 0.88 ± 0.14 mg kg–1 minute–1, 0.92 ± 0.14 mg kg–1 minute–1 and 1.45 ± 0.28%, respectively. Cardiopulmonary variables remained clinically acceptable, but ketamine–propofol was associated with a significantly higher HR (p = 0.0001) and lower f R (p = 0.0001). Time to extubation did not differ among treatments. Cardiovascular and respiratory variables were maintained within normal ranges in all treatments. Coadministration of ketamine with propofol significantly reduced the induction and maintenance dose of propofol. [ABSTRACT FROM AUTHOR]

Stick-tight fleas, Echidnophaga gallinacea (Westwood), are major ectoparasites of domesticated chickens and can cause serious diseases and even death if left untreated. In the present study the flea samples were collected from three traditional chicken-raising farms in the Al-Baha region. The samples were examined under a stereomicroscope and identified using classification keys. After extracting DNA from the insects, the polymerase chain reaction technique was used to identify the hereditary gene, cytochrome oxidase, present in the insect biopics. The gene was purified, its nucleotide sequence was obtained, and the accession number (OR161051) has been assigned in GenBank. After determining its nucleotide sequence, it was compared with other insects in GenBank, where it was found to be identical (99.82%) to the E. gallinacea isolate from Thailand recorded in GenBank [OQ291364 and MW492259 (https://www.ncbi.nlm.nih.gov/nucleotide/MW492259.1?report=genbank&log$=nucltop&blast%5frank=1&RID=VJR9ZAEE013)]. The match was 94.33% with Echidnophaga iberica from Spain (KF479239) and 93.97% with Echidnophaga oschanini from China (KU880666). The phylogenetic tree also showed similarities between the Saudi Arabian isolates and other isolates. This genetic study of sticktight fleas is the first of its kind in the Kingdom of Saudi Arabia, therefore will be valuable for assessing the prevalence and geographical distribution of this parasite. [ABSTRACT FROM AUTHOR]

1. The purpose of this meta-analysis was to evaluate the effect of mannan oligosaccharide (MOS) as an alternative to antibiotic growth promoters (AGP) on feed intake (FI), body weight gain (BWG), and feed conversion ratio (FCR) of broilers.2. Data from 75,594 broilers were extracted from 17 articles (19 trials) published between January 2010 and March 2023. The main criteria for the publication selection were as follows, at least three treatments applied (negative control group without MOS or AGP versus MOS or AGP supplementation), presence of performance results, and intra-experimental variation associated with the mean of response (such as standard error). Treatments were classified as control, MOS, or AGP, and adjusted means of treatment were compared. Additionally, the average daily gain (ADG) and average daily feed intake (ADFI) of each type of supplementation were calculated relative (Δ) to the control group (ΔADFI and ΔADG) and expressed as a percentage of the difference.3. Broilers receiving a diet supplemented with MOS had a 3.7% better BWG and 3% better FCR compared to the control diet (P < 0.001), but these variables were similar to the group receiving AGP supplementation. No significant difference was detected in FI among treatments (P > 0.050). The relationship between ΔADG and ΔADFI was linear for the MOS and AGP-supplemented group (P < 0.050). The ΔADG of broilers fed diets supplemented with MOS or AGP was 6.4% and 4.54% when ΔADFI was zero, respectively. The ΔADG of MOS increased by 0.58% for every 1% of increasing observed in ΔADFI. The corresponding value for the increased ΔADG for the AGP group was 0.69%.4. The results of this meta-analysis indicated that MOS supplementation is effective in increasing BWG and reducing FCR, similar to broilers fed a diet supplemented with AGP. Therefore, MOS is a safe and sustainable alternative for AGP-free poultry production. [ABSTRACT FROM AUTHOR]

AbstractNecrotic enteritis (NE) is a severe gastrointestinal disease that poses a significant threat to poultry, leading to progressive deterioration of the small intestine, reduced performance, and increased mortality rates, causing economic losses in the poultry industry. The elimination of antimicrobial agents from chicken feed has imposed a need to explore alternative approaches for NE control, with vaccination emerging as a promising strategy to counteract the detrimental consequences associated with NE. This comprehensive study presents an overview of the extensive efforts made in NE vaccination from 2004 to2023. The study focuses on the development and evaluation of vaccine candidates designed to combat NE. Rigorous evaluations were conducted in both laboratory animals and broiler chickens, the target population, to assess the vaccines’ capacity to elicit an immune response and provide substantial protection against toxin challenges and experimental NE infections. The review encompasses the design of vaccine candidates, the antigens employed, in vivo immune responses, and the efficacy of these vaccines in protecting birds from experimental NE infection. This review contributes to the existing knowledge of NE vaccination strategies, offering valuable insights for future research and development in this field. [ABSTRACT FROM AUTHOR]

Fatty liver disease is a common metabolic disease in chickens. This disease can lead to a decrease in egg production and increase the risk of death in chickens. Long non‐coding RNAs (lncRNAs) are involved in fatty liver formation by directly targeting genes or regulating gene expression by competitively binding microRNAs. However, a large proportion of competing endogenous RNA (ceRNA) networks in fatty liver diseases are still unclear. The total of 300 Jingxing‐Huang chickens were used for fatty liver model construction. Then, differentially expressed (DE) genes (DEGs) identified through whole‐transcriptome sequencing from four chickens with fatty liver and four chickens without fatty liver were chosen from the F1 generation. A total of 953 DEGs were identified between the fatty liver group and the control group, including 26 DE micro (mi)RNAs and 56 DE lncRNAs. Differential expression heatmaps and volcano plots were obtained after clustering expression analysis. Gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed that these DEGs were involved in many biological processes and signaling pathways related to fatty acid metabolism and lipid synthesis. Furthermore, cytoscape was used to construct a ceRNA network of the DE miRNAs, DE mRNAs, and DE lncRNAs. Eleven DE lncRNAs, seven DE miRNAs, and 13 DE mRNAs were found to be associated with the pathogenesis of fatty liver disease. An lncRNA–miRNA–mRNA ceRNA network was constructed to elucidate the mechanisms of fatty liver diseases, and the ENSGALT00000079786‐miR‐140/miR‐143/miR‐1a/miR‐22/miR‐375 network was identified. These results provide a valuable resource for further elucidating the posttranscriptional regulatory mechanisms of chicken liver and adipose fat development or deposition. [ABSTRACT FROM AUTHOR]

The poultry population is an integral part of Ethiopia’s Gross Domestic Product (GDP) but, due to various infectious diseases such as infectious bursal disease (IBD), the expected economic impact in the country remains limited. The status of the disease in Ethiopia is obscured; thus, a systematic review and meta-analysis were employed to estimate the overall pooled prevalence of IBD in Ethiopia. Meta-analysis was conducted to determine the effects of each identified risk factor, while meta-regression and sub-group analysis were employed to assess the relationship between study-level covariates and effect size. The pooled prevalence of IBD in Ethiopia was 69.4% (95% CI 30.7–96.2), while the pooled logit prevalence was 0.94 (95% CI: 0.68–1.20) with significant inter-study variance (Q test = 948.28, df = 43, P < 0.001; τ2 = 0.71, I2 = 95.47%). A small-study effect was detected in the regression-based Egger test (Prob > |z| < 0.0001). Significant variation was observed among different groups such as sex, age, breed, and type of farm of the chickens. The effect size for the study period from 2018 to 2021 was significantly lower by −0.204 compared to the study period from 2009 to 2015 (P < 0.0001. In conclusion, the IBD pooled prevalence estimate is high, even though the number of studies in the country is insufficient. The high prevalence of the disease requires prompt attention from all stakeholders in the sector to bring it under control through comprehensive disease prevention and control intervention strategies. [ABSTRACT FROM AUTHOR]

Background: Colibacillosis in broiler chickens is associated with economic loss and localized or systemic infection. Usually, the last resort is antibacterial therapy. Insight into the disease pathogenesis, host responses and plausible immunomodulatory effects of the antibacterials is important in choosing antibacterial agent and optimization of the treatment. Selected responses of broiler chickens experimentally infected with Escherichia coli (E. coli) and also those treated with florfenicol are evaluated in this study. Chickens (n = 70, 5 weeks old) were randomly assigned to four groups. The control groups included normal control (NC) and intratracheal infection control (ITC) (received sterile bacterial medium). The experimental groups consisted of intratracheal infection (IT) that received bacterial suspension and intratracheal infection with florfenicol administration (ITF) group. Results: Florfenicol reversed the decreased albumin/globulin ratio to the level of control groups (p > 0.05). Serum interleukin 10 (IL-10) and interferon‐gamma (IFN-γ) concentrations decreased in IT birds as compared to NC group. Florfenicol decreased the serum interleukin 6 (IL-6) concentration as compared to IT group. Milder signs of inflammation, septicemia, and left shift were observed in the leukogram of the ITF group. Florfenicol decreased the severity of histopathological lesions in lungs and liver. Depletion of lymphoid tissue was detected in spleen, thymus and bursa of IT group but was absent in ITF birds. The number of colony forming units of E. coli in liver samples of ITF group was only slightly lower than IT birds. Conclusions: Experimental E. coli infection of chickens by intratracheal route is associated with remarkable inflammatory responses as shown by changes in biochemical and hematological parameters. Histopathological lesions in lymphoid organs (especially in the spleen) were also prominent. Florfenicol has positive immunomodulatory effects and improves many of the lesions before the full manifestation of its antibacterial effects. These effects of florfenicol should be considered in pharmacotherapy decision-making process. [ABSTRACT FROM AUTHOR]

India is ranked as the 2nd largest egg producer in the world. Despite the prevalence of backyard poultry (free range), a majority of the commercial egglaying hens in the country are still housed in battery cages. There is a global shift toward cage-free eggs, due to regulations and increased demand from conscious consumers and food corporations. However, there are very few commercial cage-free facilities in India to meet this demand. The aim of this study was to undertake a needs-assessment survey of Indian egg producers on cage-free production, and understand what support is needed to build the capacities of the cage-free egg production sector to develop it into a viable and sustainable alternative to battery cage eggs. The results showed that nearly all producers agreed on the need for additional support in shifting to, and operating in, the cage-free sector. This included support in the form of financial assistance, technical training, and promotion of the cage-free sector. The results of this study highlight the pressing need for government and private support, in the absence of which cage-free producers are compelled to compete with battery cage poultry producers on prices, which will result in increased losses and failure of the sector, since they have not yet achieved economies of scale. [ABSTRACT FROM AUTHOR]

Simple Summary: The widespread use of antibiotics in poultry production has raised public concerns about food safety and meat quality. This study investigated the effects of early ciprofloxacin use on Xueshan chickens, focusing on growth, meat quality, and metabolic changes. It was found that, while ciprofloxacin treatment did not affect overall chicken growth, it significantly altered meat quality characteristics, which may affect meat texture and preservability. Although ciprofloxacin residues were not detected in muscle, metabolic analyses revealed significant metabolic alterations, particularly in microbial and amino acid metabolism pathways. These findings emphasize that antibiotic use may have far-reaching effects on poultry product quality, involving not only direct meat quality changes but also complex metabolic reactions. This study provides new perspectives for understanding the role of antibiotics in poultry production, which is important for optimizing antibiotic-use strategies and ensuring food safety. The results may be an important reference for poultry producers, food safety regulators and consumers. To investigate the effects of early administration of ciprofloxacin (CIP) on Xueshan chickens, in this study Xueshan chickens were measured for growth performance, tested for drug residues, evaluated for meat quality, and muscle metabolism changes were explored using a non-target metabolomics approach. Experimental findings revealed that early CIP use did not significantly impact the overall growth rate of Xueshan chickens (p > 0.05). However, notable alterations in meat quality were observed: the CIP-treated group exhibited a significant decrease in muscle pH (pH1 and pH24) and a marked increase in drip loss and moisture content (p > 0.05). No CIP residues were detected in muscle tissue. Untargeted metabolomics analyses unveiled significant alterations in the metabolic profile of market-age chickens following CIP treatment. Both functional enrichment and metabolic network analyses indicated significant effects on the ko01120 (microbial metabolism in diverse environments) and ko00350 (tyrosine metabolism) pathways, implying that CIP treatment may influence chicken meat quality by modulating microbial communities and amino acid metabolism. This study provides a crucial foundation for understanding the impact of antibiotics on meat quality and metabolism in poultry production, offering scientific insights for optimizing antibiotic-use strategies and safeguarding poultry product quality. [ABSTRACT FROM AUTHOR]

Simple Summary: This study investigates how different housing systems affect daily step counts and their impact on body conformation, carcass traits, meat quality, and serum biochemical parameters of Jiuyuan Black chickens. Chickens were monitored from 60 to 150 days old, with step counts recorded using pedometers. The study showed that free-range chickens with high step counts had significantly higher daily and total steps compared to other groups, as well as higher heart weight, lower abdominal fat, and better meat quality, but lower intramuscular fat. The CK and LDH levels in chickens exhibited an almost consistent upward trend as exercise levels increased. Overall, free-range chickens with more exercise volume improved heart weight and reduced fat but negatively impacted some body measurements and meat quality. These findings help in choosing housing systems for Chinese indigenous chickens. This study aims to investigate the dynamic changes in daily step counts under different housing systems and further explore the effects of housing system on the body conformation, carcass traits, meat quality, and serum biochemical parameters of a Chinese indigenous chicken breed. At 60 d of age, 300 Jiuyuan Black male chickens with similar body weights in each housing system were further raised until the age of 150 d. At 90, 120, and 150 d of age, in both cage-reared and free-range systems, the top 20 chickens with the highest step counts measured using pedometers and the bottom 20 chickens with the lowest step counts were designated as the cage high-steps group (CHS), the cage low-steps group (CLS), the free-range high-steps group (FHS), and the free-range low-steps group (FLS), respectively. The results show that, at any age stage, the average daily steps (ADS) and total steps (TS) of the FHS group are significantly higher than the other three groups (p < 0.05). The TS of almost all groups showed an overall downward trend as the age increased. Increased exercise volume results in reduced shank length (90 d), breast width (90 d), and keel length (150 d) (p < 0.05). Only birds at 90 d of age from the FHS and FLS groups exhibited lower live body weight, carcass weight, half-eviscerated weight, eviscerated weight, breast muscle weight, leg muscle weight, and percentage of eviscerated weight than the CLS group (p < 0.05). Birds from the FHS group showed the highest heart weight values but the lowest abdominal fat weight values among these four groups (p < 0.05). Both the breast and leg muscle samples from the FHS group displayed higher dry matter and shear force than those from the CHS and CLS groups (p < 0.05). The FHS group displayed the lowest intramuscular fat among the four groups (p < 0.05). The creatine kinase (CK) and lactate dehydrogenase (LDH) levels in chickens of all age stages were almost observed to rise with increased physical activity. In conclusion, free-range chickens with more exercise volume exhibited an elevated heart weight and reduced abdominal fat but showed negative effects on some body measurements and carcass traits. These results can provide a theoretical basis for the selection of different housing systems for Chinese indigenous chickens. [ABSTRACT FROM AUTHOR]

Simple Summary: Cooling rooster semen to a temperature of 5 °C is a technique utilized to extend the preservation period of sperm. However, rooster sperm is highly susceptible to damage during preservation, which involves numerous sources of oxidative stress from dilution, limiting its viability and fertility potential to less than 24 h under cool storage conditions. Therefore, researchers are continuously working to optimize preservation methods to enhance the viability and longevity of rooster semen. The aim of this study was to investigate the effectiveness of Aloe vera gel, known for its beneficial antioxidant properties, on the quality of cooled semen in Thai native roosters (Pradu Hang Dum) and to evaluate the fertility rate after artificial insemination. The results showed that Aloe vera gel contained various bioactive compounds with antioxidant activity. The supplementation of the extender with 1.0% Aloe vera gel proved to be beneficial, reducing lipid peroxidation and simultaneously improving sperm quality during cold storage at 5 °C for up to 72 h. The cooling of semen storage at 5 °C from a Thai native rooster (Pradu Hang Dum), supplemented with herbs possessing antioxidant properties, provided limited research. This study was conducted to evaluate the efficiency of Aloe vera (AV) gel supplementation at various levels on the quality of cooled semen and subsequent fertility after artificial insemination. Sixty-four chickens had semen pooled, diluted, and supplemented with different levels of AV gel (0% as control, 0.25%, 0.50%, 1.0%, 2.5%, 5.0%, 10%, and 20%), and then stored for 72 h. In Experiment 1, semen quality, malondialdehyde (MDA) levels, and pH values were assessed at 0, 24, 48, and 72 h after storage. Experiment 2 assessed fertility potential using the most effective cooled storage semen from Experiment 1. Results showed a decrease in semen quality with prolonged storage time (p < 0.001). The highest semen quality was observed in the group supplemented with 1.0% AV gel (p < 0.001), whereas the lowest was noted in the 20% AV gel group (p < 0.001). Furthermore, the 1.0% AV gel group exhibited the highest semen quality at 24, 48, and 72 h of storage. The evaluation of fertility and hatchability rates revealed a statistically significant improvement in fertility potential (p < 0.05) in the group supplemented with 1.0% AV gel. In summary, this study represents the first investigation of stored Thai native rooster semen using a semen extender supplemented with Aloe vera gel at 5 °C, demonstrating its efficacy for storage up to 72 h. The addition of 1% AV gel was recommended as an antioxidant supplementation during the semen storage process at 5 °C to enhance semen quality and fertility rates. [ABSTRACT FROM AUTHOR]

Simple Summary: This study aimed to evaluate the pathogenicity of duck adenovirus Type 3 (DAdV-3) in chickens. In this study, this virus was identified through the amplification of specific viral fragments and whole-genome sequencing, and its pathogenicity was identified by means of its inoculation into chickens. The isolated DAdV-3 led to higher pathogenicity and fatality rates in chickens. The main clinical symptoms in the sacrificed chicks were hepatitis–hydropericardium syndrome (HHS), swollen and petechial hemorrhages of the bursa, and the gizzard's endothelium falling off easily. Histopathological examination showed swelling, necrosis, lymphocyte infiltration, and basophilic inclusion bodies in multiple organs. Higher antibody levels were found in the surviving chickens. The major variation domains (ORF19B, ORF66, and ORF67) did not change after infection with the virus in Muscovy ducks and chickens. This is the first study to report the pathogenicity of DAdV-3 in chickens, and it provides an experimental basis for newly infected hosts of DAdV-3. Duck adenovirus Type 3 (DAdV-3) severely affects the health of ducks; however, its pathogenicity in chickens remains unknown. The objectives of this study were to evaluate the pathogenicity and major pathological changes caused by DAdV-3 in chickens. Viral DNA was extracted from the liver of the Muscovy duck, and the fiber-2 and hexon fragments of DAdV-3 were amplified through polymerase chain reaction (PCR). The evolutionary tree revealed that the isolated virus belonged to DAdV-3, and it was named HE-AN-2022. The mortality rate of chicks that received inoculation with DAdV-3 subcutaneously via the neck was 100%, while the mortality rate for eye–nose drop inoculation was correlated with the numbers of infection, with 26.7% of chicks dying as a result of exposure to multiple infections. The main symptoms exhibited prior to death were hepatitis–hydropericardium syndrome (HHS), ulceration of the glandular stomach, and a swollen bursa with petechial hemorrhages. A histopathological examination revealed swelling, necrosis, lymphocyte infiltration, and basophilic inclusion bodies in multiple organs. Meanwhile, the results of quantitative real-time PCR (qPCR) demonstrated that DAdV-3 could affect most of the organs in chickens, with the gizzard, glandular stomach, bursa, spleen, and liver being the most susceptible to infection. The surviving chicks had extremely high antibody levels. After the chickens were infected with DAdV-3 derived from Muscovy ducks, no amino acid mutation was observed in the major mutation regions of the virus, which were ORF19B, ORF66, and ORF67. On the basis of our findings, we concluded that DAdV-3 infection is possible in chickens, and that it causes classic HHS with ulceration of the glandular stomach and a swollen bursa with petechial hemorrhages, leading to high mortality in chickens. The major variation domains did not change in Muscovy ducks or in chickens after infection. This is the first study to report DAdV-3 in chickens, providing a new basis for preventing and controlling this virus. [ABSTRACT FROM AUTHOR]

In the avian species, genetic modification by cell nuclear transfer is infeasible due to its unique reproductive system. The in vitro primordial germ cell modification approach is difficult and cumbersome, although it is the main method of genetic modification in chickens. In the present study, the adenoviral CRISPR/Cas9 vector was directly microinjected into the dorsal aorta of chicken embryos to achieve in vivo genetic modification. The results demonstrated that keratin 75-like 4 (KRT75L4), a candidate gene crucial for feather development, was widely knocked out, and an 8bp deletion was the predominant mutation that occurred in multiple tissues in chimeras, particularly in the gonad (2.63–11.57%). As we expected, significant modification was detected in the sperm of G0 (0.16–4.85%), confirming the potential to generate homozygous chickens and establishing this vector as a simple and effective method for genetic modification in avian species. [ABSTRACT FROM AUTHOR]

Numerous studies have evidenced that neuropsychiatric disorders (mental illness and emotional disturbances) with aggression (or violence) pose a significant challenge to public health and contribute to a substantial economic burden worldwide. Especially, social disorganization (or social inequality) associated with childhood adversity has long-lasting effects on mental health, increasing the risk of developing neuropsychiatric disorders. Intestinal bacteria, functionally as an endocrine organ and a second brain, release various immunomodulators and bioactive compounds directly or indirectly regulating a host's physiological and behavioral homeostasis. Under various social challenges, stress-induced dysbiosis increases gut permeability causes serial reactions: releasing neurotoxic compounds, leading to neuroinflammation and neuronal injury, and eventually neuropsychiatric disorders associated with aggressive, violent, or impulsive behavior in humans and various animals via a complex bidirectional communication of the microbiota–gut–brain (MGB) axis. The dysregulation of the MGB axis has also been recognized as one of the reasons for the prevalence of social stress-induced injurious behaviors (feather pecking, aggression, and cannibalistic pecking) in chickens. However, existing knowledge of preventing and treating these disorders in both humans and chickens is not well understood. In previous studies, we developed a non-mammal model in an abnormal behavioral investigation by rationalizing the effects of gut microbiota on injurious behaviors in chickens. Based on our earlier success, the perspective article outlines the possibility of reducing stress-induced injurious behaviors in chickens through modifying gut microbiota via cecal microbiota transplantation, with the potential for providing a biotherapeutic rationale for preventing injurious behaviors among individuals with mental disorders via restoring gut microbiota diversity and function. [ABSTRACT FROM AUTHOR]

Newcastle disease (ND) is caused by virulent strains of avian paramyxovirus type 1, also known as Newcastle disease virus (NDV). Despite vaccination, the frequency of reported outbreaks in Ethiopia has increased. From January to June 2022, an active outbreak investigation was conducted in six commercial chicken farms across areas of central Ethiopia to identify the circulating NDV strains. Thirty pooled tissue specimens were collected from chickens suspected of being infected with NDV. A questionnaire survey of farm owners and veterinarians was also carried out to collect information on the farms and the outbreak status. NDV was isolated using specific-pathogen-free (SPF)-embryonated chicken eggs and detected using haemagglutination and the reverse transcriptase–polymerase chain reaction (RT–PCR). The genotype and virulence of field NDV isolates were determined using phylogenetic analysis of fusion (F) protein gene sequences and the mean death time (MDT) test in SPF-embryonated chicken eggs. The questionnaire results revealed that ND caused morbidity (23.1%), mortality (16.3%), case fatality (70.8%), and significant economic losses. Eleven of thirty tissue specimens tested positive for NDV using haemagglutination and RT–PCR. The MDT testing and sequence analysis revealed the presence of virulent NDV classified as genotype VII of class II velogenic pathotype and distinct from locally used vaccine strains (genotype II). The amino acid sequences of the current virulent NDV fusion protein cleavage site motif revealed 112RRQKR↓F117, unlike the locally used avirulent vaccine strains (112GRQGR↓L117). The epidemiological data, MDT results, cleavage site sequence, and phylogenetic analysis all indicated that the present NDV isolates were virulent. The four NDV sequences were deposited in GenBank with accession numbers F gene (PP726912-15) and M gene (PP726916-19). The genetic difference between avirulent vaccine strains and circulating virulent NDV could explain the low level of protection provided by locally used vaccines. Further studies are needed to better understand the circulating NDV genotypes in different production systems. [ABSTRACT FROM AUTHOR]

Simple Summary: This study provides a historical perspective of climate change in relation to chickens and a review of genetic advancements related to heat tolerance in chickens. It highlights the origin of the chickens and how the process of domestication and selective breeding has resulted in genetic variations and increased vulnerability to heat stress. This review also discusses the protective genes and molecular mechanisms, such as heat shock proteins, antioxidants, and immunological response that contribute to heat stress tolerance. Likewise, it discusses the use of further genomic techniques such as the genome-wide association study (GWAS) and quantitative trait locus (QTL) analysis in the identification of genetic variables that contribute to the breeding of broiler chickens with enhanced heat tolerance. Similarly, it highlights the need for including local chickens in breeding programs to enhance genetic diversity. This would help them to better withstand heat stress, addressing the challenge of sustainable poultry production in the context of global warming. Climate change poses a significant threat to the poultry industry, especially in hot climates that adversely affect chicken growth, development, and productivity through heat stress. This literature review evaluates the evolutionary background of chickens with the specific genetic characteristics that can help chickens to cope with hot conditions. Both natural selection and human interventions have influenced the genetic characteristics of the breeds used in the current poultry production system. The domestication of chickens from the Red junglefowl (Gallus gallus) has resulted in the development of various breeds with distinct genetic differences. Over the past few years, deliberate breeding for desirable traits (such as meat production and egg quality) in chickens has resulted in the emergence of various economically valuable breeds. However, this selective breeding has also caused a decrease in the genetic diversity of chickens, making them more susceptible to environmental stressors like heat stress. Consequently, the chicken breeds currently in use may possess a limited ability to adapt to challenging conditions, such as extreme heat. This review focuses on evaluating potential genes and pathways responsible for heat tolerance, including heat shock response, antioxidant defense systems, immune function, and cellular homeostasis. This article will also discuss the physiological and behavioral responses of chicken varieties that exhibit genetic resistance to heat, such as the naked neck and dwarf traits in different indigenous chickens. This article intends to review the current genomic findings related to heat tolerance in chickens that used methods such as the genome-wide association study (GWAS) and quantitative trait loci (QTL) mapping, offering valuable insights for the sustainability of poultry in the face of global warming. [ABSTRACT FROM AUTHOR]

Simple Summary: Thermographic monitoring of the back surface of broiler grillers and the environment are accurate indicators of thermal comfort, allowing production to be enhanced and ensuring the quality of the final product. In this scenario, infrared thermography was used to evaluate chickens' thermophysiological state related to bird density, lineage, age, and time of day, isolated or integrated, on dorsal surface temperature, performance and carcass condemnations of broiler grillers reared in a Dark House system. The main results revealed that the dorsal surface temperature in the broiler grillers was affected by the combined effects of age and time of day, lineage and density, and lineage and age. The increase in the density of broiler grillers did not negatively influence mortality, average daily weight gain, and carcass condemnation. However, partial condemnations and arthritis condemnations were influenced by the lineage. The aims of this study were (i) to evaluate the effect of density, lineage, age, and time of day on dorsal surface temperature and (ii) to evaluate the effect of density and lineage on performance and carcass condemnations in broiler grillers. The evaluations were carried out in barns with the Dark House system, with two densities, 17 and 19 chickens/m2 and two lineages, Cobb and Ross. The dorsal surface temperature of the chickens was measured by infrared thermography at 7, 14, 21, 23, 25 and 27 days of age, four times a day. The average daily weight gain, feed conversion, mortality, partial carcass condemnations, as well as those due to arthritis and dermatosis were also evaluated. The highest dorsal surface temperatures were observed in Cobbs housed at a density of 17 chickens/m2, and in Ross housed at a density of 19 chickens/m2. Cobbs housed at a 17 chickens/m2 density showed the lowest feed conversion compared to Ross at the same density. Ross showed higher dorsal surface temperatures when compared to Cobbs at 14, 21, and 27 days. Cobbs showed higher percentages of partial carcass condemnation and arthritis compared to Ross. The higher density of broiler grillers in the Dark House system does not influence the dorsal surface temperature, performance, dermatosis, arthritis, and partial carcass condemnations. [ABSTRACT FROM AUTHOR]

Skeletal muscle, which is predominantly constituted by multinucleated muscle fibers, plays a pivotal role in sustaining bodily movements and energy metabolism. Myoblasts, which serve as precursor cells for differentiation and fusion into muscle fibers, are of critical importance in the exploration of the functional genes associated with embryonic muscle development. However, the in vitro proliferation of primary myoblasts is inherently constrained. In this study, we achieved a significant breakthrough by successfully establishing a chicken myoblast cell line through the introduction of the exogenous chicken telomerase reverse transcriptase (chTERT) gene, followed by rigorous G418-mediated pressure screening. This newly developed cell line, which was designated as chTERT-myoblasts, closely resembled primary myoblasts in terms of morphology and exhibited remarkable stability in culture for at least 20 generations of population doublings without undergoing malignant transformation. In addition, we conducted an exhaustive analysis that encompassed cellular proliferation, differentiation, and transfection characteristics. Our findings revealed that the chTERT-myoblasts had the ability to proliferate, differentiate, and transfect after multiple rounds of population doublings. This achievement not only furnished a valuable source of homogeneous avian cell material for investigating embryonic muscle development, but also provided valuable insights and methodologies for establishing primary cell lines. [ABSTRACT FROM AUTHOR]

Foodborne pathogens pose a persistent threat in broiler chicken production, particularly during the slaughter process, where contamination with zoonotic pathogens remains a concern. This study focuses on the potential of organic acids, such as formic and lactic acid, and the oxidizing agent peracetic acid, to decontaminate scalding water and enhance the hygiene of chicken carcasses. We conducted suspension tests introducing various organic loads to mirror the conditions of practical scalding water. Additionally, the surface tests were performed on chicken skin. Both methods were further tested in an experimental slaughtering facility. In suspension tests, the organic acids achieved impressive decontamination, with a 5‐log10 reduction of the test organisms Enterococcus hirae, Salmonella Typhimurium and Campylobacter jejuni at minimal concentrations (between 0.04% and 2% for formic acid; between 0.1% and 4.5% for lactic acid). Peracetic acid also effectively sanitized model water and chicken skin, even when used in low concentrations (between 0.001% and 0.1%), both in the laboratory‐based testing and in the experimental slaughtering facility. These results suggest that the tested disinfectants can effectively sanitize process water, even under conditions mimicking practical scalding water with organic matter. Peracetic acid, in particular, proved highly effective in improving chicken skin hygiene even at low concentrations. [ABSTRACT FROM AUTHOR]

1. Non-coding RNAs, such as miRNAs, play a crucial role in chicken feather growth rate. However, circular RNA (circRNA) expression profiles in fast- and slow-feathering chickens that follow and do not follow Mendelian inheritance are unclear. 2. The circRNA expression profiles was analysed by RNA sequencing of hair follicles of slow-feathering chickens that follow genetic rules and fast-feathering chickens that did not follow genetic rules. Differentially expressed circRNA-miRNA-mRNA competing endogenous RNA (ceRNA) network was then constructed and the key factors and regulation mechanisms controlling feather growth rate were identified. 3. The results revealed that 67 circRNAs were significantly differentially expressed in hens, including 22 up-regulated and 45 down-regulated circRNAs in non-Mendelian inheritance-mediated fast-feathering hens compared with Mendelian inheritance-mediated slow-feathering hens. In addition, 16 significantly differentially expressed circRNAs were identified in cockerels, including nine up-regulated and seven down-regulated circRNAs in non-Mendelian inheritance-mediated fast- compared with Mendelian inheritance-mediated slow-feathering cocks. Moreover, circRNA-mediated ceRNA regulation of hair follicle formation was particularly abundant in the Jak-STAT, Wnt and Toll-like receptor signalling pathways. Furthermore, circABI3BP was seen to be a crucial circRNA in regulating feather growth rate, by binding with gga-miR-1649-5p to regulate SSTR2 expression. 4. In conclusion, this study analysed circRNA expression profiles in fast- and slow-feathering chickens that follow and do not follow Mendelian inheritance, which laid the foundation for understanding the role of circRNA in chicken feather growth rate. [ABSTRACT FROM AUTHOR]

1. Skeletal muscle is an important component of chicken carcass. In chickens, the number of muscle fibres is fixed during the embryonic period, and muscle development during the embryonic period determines the muscle development potential after hatching. 2. Beijing-You (BY) and Cornish (CN) chickens show completely different growth rates and body types, and two breeds were used in this study to explore the role of lncRNAs in muscle development during different chicken embryonic periods. A systematic analysis of lncRNAs and mRNAs were conducted in the pectoral muscle tissues of BY and CN chickens at embryonic days 11 (ED11), 13 (ED13), 15 (ED15), 17 (ED17), and 1-day-old (D1) using RNA-seq. A total of 4,104 differentially expressed transcripts (DETs) were identified among the five stages, including 2,359 lncRNAs and 1,745 mRNAs. 3. The number of DETs between the two breeds at ED17 (1,658 lncRNAs and 1,016 mRNAs) was much higher than the total number of DET at all the other stages (692 lncRNAs and 729 mRNAs), indicating that the two breeds show the largest difference in gene regulation at ED17. 4. Correlation analysis was performed for all differentially expressed lncRNAs and mRNAs during the five periods. Forty-three, cis interaction pairs of lncRNA-mRNA related to chicken muscle development were predicted. The expression of four pairs was verified, and the results showed MSTRG.12395.2-FGFBP2 and MSTRG.18590.6-FMOD were significantly up-regulated in CN at ED11 compared to BY and might be important candidate genes for embryonic muscle development. [ABSTRACT FROM AUTHOR]

1. The accumulation of excessive fat plays a role in the development of non-alcoholic fatty liver disease (NAFLD) and phytogenic feed additives have the potential to ameliorate this. This study involved the isolation and culture of primary hepatocytes from chicken embryos to establish a model of hepatic steatosis induced by oleic acid/dexamethasone (OA/DEX). Lipid accumulation and cell viability were assessed using Nile Red staining, Oil Red O staining and cell count Kit −8 (CCK8) following treatment with varying concentrations of quercetin (Que). The potential mechanism by which Que exerts its effects was preliminarily investigated. 2. The results indicated that OA effectively treated lipid accumulation in hepatocytes. There was no notable variance in cell proliferation between the normal and OA/DEX groups when subjected to Que treatment at concentrations of 1000 ng/ml and 10 000 ng/ml. Triglycerides and cholesterol (low and high density) decreased with Que treatment, with the most substantial reduction observed at 10 000 ng/ml. 3. Gene expression levels decreased to levels similar to those in the control groups. Western blot data demonstrated that sterol regulatory element-binding protein 1 (SREBP-1) protein expression correlated with its mRNA expression level. Que mitigated lipid accumulation through the alpha serine/threonine protein kinase (AKT) and extracellular signal-regulated kinase (ERK) pathways. Expression levels of lipid-related genes (APOB, PPARα, CYP3A5 and SREBP-1) decreased to levels similar to the control groups. Western blot data demonstrated that the SREBP-1 protein expression correlated with its mRNA expression level. 4. Supplementation with Que ameliorated lipid accumulation through AKT and ERK signalling pathway in OA/DEX-induced high-fat hepatocytes. [ABSTRACT FROM AUTHOR]

1. The objective of this study was to test the dose response of dietary supplementation with algae extracts rich in marine-sulphated polysaccharides (MSP1 and MSP2) on the growing performance, body composition at slaughter and caecal microbiota of broiler chickens. 2. Male broiler Ross 308 chicks 1-d-old were distributed into eight groups, a control group (unsupplemented), four groups supplemented with increasing doses of algae extract MSP1 (40, 81, 121 and 162 g/ton feed) and three groups supplemented with increasing doses of algae extract MSP2 (40, 81 and 162 g/ton feed). Each group comprised six pens of 56 chickens. 3. All chickens were reared under challenging conditions, i.e. high rearing density of 42 kg/m2, fed growing and finishing diets containing, palm oil, rye and high levels of wheat and subjected to short daily fasting periods. The growth performance was recorded during rearing. At 10, 22 and 31 d of age, 12 chickens per group were euthanised to collect the caecal contents and determine microbiota composition and short-chain fatty acid levels. At d 35, the quality of litter and the condition of feathers, footpads and tarsals were scored. At d 36, 7 chickens per pen were slaughtered under commercial conditions to determine carcass composition and breast meat quality (ultimate pH and colour). 4. Algal extract MSP1 increased the weight of the caeca and butyrate concentration in the caeca at d 22 (p ≤ 0.05). It increased the ultimate pH of breast fillet measured after slaughter at d 36 (p ≤ 0.05). Moreover, the group receiving 162 g/t MSP1 had a more diverse microbiota at d22. However, algal extract MSP2 had negligible effect on the different measured parameters. [ABSTRACT FROM AUTHOR]

Oxidative stress is recognized as a prominent factor contributing to follicular atresia and ovarian aging, which leads to decreased laying performance in hens. Reducing oxidative stress can improve ovarian function and prolong the laying period in poultry. This study investigates the impact of Pterostilbene (PTS), a natural antioxidant, on ovarian oxidative stress in low-laying chickens. Thirty-six Hy-Line White laying chickens were evenly divided into four groups and fed diets containing varying doses of PTS for 15 consecutive days. The results showed that dietary supplementation with PTS significantly increased the laying rate, with the most effective group exhibiting a remarkable 42.7% increase. Furthermore, PTS significantly enhanced the antioxidant capacity of aging laying hens, as evidenced by increased levels of glutathione, glutathione peroxidase, superoxide dismutase, catalase, and total antioxidant capacity in the ovaries, livers, and serum. Subsequent experiments revealed decreased expressions of Bax, Caspase-3, and γ-H2AX, along with an increased expression of BCL-2 in the ovaries and livers of laying hens. PTS supplementation also positively affects fat metabolism by reducing abdominal fat accumulation and promoting fat transfer from the liver to the ovary. To elucidate the mechanism underlying the effects of PTS on ovarian function, a series of in vitro experiments were conducted. These in vitro experiments revealed that PTS pretreatment restored the antioxidant capacity of D-galactose-induced small white follicles by upregulating SIRT1/Nrf2 expression. This protective effect was inhibited by EX-527, a specific inhibitor of SIRT1. These findings suggest that the natural antioxidant PTS has the potential to regulate cell apoptosis and fat metabolism in laying chickens by ameliorating oxidative stress, thereby enhancing laying performance. [ABSTRACT FROM AUTHOR]

Problem statement: As the intestinal function is intimately affected by fed diets, many kinds of natural substances, prebiotics and probiotics have been supplemented to broilers to increase poultry production by activating intestinal function. The aim of this study was to investigate whether Bacillus subtilis could improve the growth performance and serum biochemistry in broiler chicken. Approach: A total of 200 broiler chicks were randomly assigned to 4 treatment groups, consisting of 2 replicates of 25 birds each. Commercial mash pre-starter, starter and finisher diets were supplemented with 50, 100 and 150 ppm of B. subtilis. Results: Body weight gain was better in all the experimental groups than the control. The growth performance was increased in 150 ppm of B. subtilis. Total cholesterol and Triglycerides were decreased, HDL, Serum Glutamine Pyruvic Transaminase (SGPT), Serum Glutamic Oxaloacetic Transaminase (SGOT) were increased. Conclusion: This study shows that adding B. subtilis to the broiler diet could improve the growth performance, increase feed efficiency and regulate serum biochemical parameters. Based on our study, it could be recommended that addition of B. subtilis at 150 ppm (150 mg/kg) could improve the growth performance of broiler chicken. [ABSTRACT FROM AUTHOR]

The influence of water-soluble selenium-containing proteins (WSSeP) in chicken on ulcerative colitis (UC) is not known. This work aims to investigate the effect of two WSSeP including h-Se with 1.78 μg Se/g and l-Se with 1.04 μg Se/g on mice UC induced by dextran sodium sulfate (DSS) versus 5-aminosalicylic acid (5-ASA). Seventy C57BL/6 mice were randomly divided into seven groups: groups 1 and 7 were given normal saline. Group 2 to group 4 were administrated orally 500, 1500, and 3000 mg/kg/day h-Se, respectively. Group 5 was given 1500 mg/kg/day l-Se as the control of group 3. From day 14 to day 21, groups 2 to 7 were fed with 3% DSS. Synchronously, group 6 was fed with 150 mg/kg/day 5-ASA. On day 21, the disease activity index, colon length, the histopathological changes, the expressions of claudin-1, occludin, ZO-1, TLR4, and MyD88 in colons, the levels of inflammatory cytokines (IFN-γ, IL-1β, IL-6, TNF-α), and antioxidant markers (LPS, GSH-Px, SOD, MDA) in serum were determined. WSSeP can effectively improve the damages of DSS to the colon, thymus, and spleen, which present protein and Se dose-dependent. 1.50 g h-Se dose can significantly promote the expression levels of claudin-1, occludin, and ZO-1, to surround crypt gland and goblet and epithelial cells and inhibit the attack of DSS, suppress TLR4/MyD88 pathway, decrease the levels of IL-1β, IL-6, TNF-α, IFN-γ, LPS, and MDA, and increase the activities of GSH-Px and SOD, which are better than those of 5-ASA. Therefore, WSSeP would be a natural and potential anti-inflammatory agent for UC. [ABSTRACT FROM AUTHOR]

Nonalcoholic fatty liver disease (NAFLD), which shows similar symptoms as fatty liver hemorrhage syndrome (FLHS) in chickens, is the most common cause of chronic liver disease and cancer in humans. NAFLD patients and FLHS in chickens have demonstrated severe liver disorders when infected by emerging strains of human hepatitis E virus (HEV) and avian HEV, respectively. We sought to develop a fatty liver disease chicken model by altering the diet of 3-week-old white leghorn chickens. The high cholesterol, and low choline (HCLC) diet included 7.6% fat with additional 2% cholesterol and 800 mg/kg choline in comparison to 5.3% fat, and 1,300 mg/kg choline in the regular diet. Our diet induced fatty liver avian model successfully recapitulates the clinical features seen during NAFLD in humans and FLHS in chickens, including hyperlipidemia and hepatic steatosis, as indicated by significantly higher serum triglycerides, serum cholesterol, liver triglycerides, cholesterol, and fatty acids. By developing this chicken model, we expect to provide a platform to explore the role of lipids in the liver pathology linked with viral infections and contribute to the development of prophylactic interventions. [ABSTRACT FROM AUTHOR]

Anthelmintic resistance in livestock animals has been spreading across the world in prevalence and severity. As a result, researchers are exploring alternative strategies to combat this issue, and one promising avenue is the utilization of medicinal plants. This study aims to investigate the anthelmintic efficacy of the crude ethanolic extract (CEE) derived from the leaves of Juglans regia against one of the most detrimental nematode parasites affecting poultry, namely Ascaridia galli (A. galli). For the in vitro studies, adult A. galli worms were collected from the naturally infected chickens and the efficacy of CEE was measured at the concentration of 25, 50, and 100 mg/ml using adult worm motility inhibition (WMI) assay. In addition, levamisole (0.55 mg/ml) was used as the positive control. Likewise, Phosphate buffered saline (PBS) was used as the negative control. For the in vivo studies, CEE of J.regia at the doses of 500, 1000, and 2000 mg/kg were evaluated in chickens experimentally infected with A. galli. The anthelmintic efficacy was monitored using faecal egg count reduction (FECR) and worm count reduction (WCR) assays. In vitro studies revealed significant (P < 0.001) anthelmintic effects of CEE of J.regia on the motility of A. galli worms at different hours post-exposure. At the concentration of 100 mg/ml, CEE resulted in 96.5% inhibition of worm motility at 24 h post-exposure. While the synthetic anthelmintic drug, levamisole caused the highest inhibition of worm motility (100%) at the same time period. The in vivo anthelmintic activity of CEE of J. regia demonstrated a maximum effect on day 14 post-treatment by inducing 67.28% FECR and 65.03% WCR. We observed no significant difference (P > 0.05) in worm counts between the negative control group and the chickens treated with CEE at the dosage of 500 mg/kg. Together, the results of the present study suggest that CEE of J. regia leaves possess anthelmintic properties and could be a potential source of novel anthelmintic compounds for controlling helminth parasites. [ABSTRACT FROM AUTHOR]

Background: The gut microbiome plays a key role in the formation of livestock and poultry traits via serum metabolites, and empirical evidence has indicated these traits are sex-linked. Methods: We examined 106 chickens (54 male chickens and 52 female chickens) and analyzed cecal content samples and serum samples by 16S rRNA gene sequencing and non-targeted metabolomics, respectively. Results: The cecal microbiome of female chickens was more stable and more complex than that of the male chickens. Lactobacillus and Family XIII UCG-001 were enriched in male chickens, while Eubacterium_nodatum_group, Blautia, unclassified_Anaerovoraceae, Romboutsia, Lachnoclostridium, and norank_ Muribaculaceae were enriched in female chickens. Thirty-seven differential metabolites were identified in positive mode and 13 in negative mode, showing sex differences. Sphingomyelin metabolites possessed the strongest association with cecal microbes, while 11β-hydroxytestosterone showed a negative correlation with Blautia. Conclusion: These results support the role of sexual dimorphism of the cecal microbiome and metabolome and implicate specific gender factors associated with production performance in chickens. [ABSTRACT FROM AUTHOR]

Respiratory RNA viruses such as Infectious bronchitis virus (IBV) and Avian metapneumovirus (aMPV), which are characterized by generating both respiratory damage and adverse effects on reproductive organs, affect poultry production economically due to high mortality rate and decrease in egg production and quality. Particularly, aMPV has three genotypes that have been reported with greater frequency in chickens: aMPV-A, aMPV-B, and aMPV-C. The present study proposes the design of a multiplex RT-qPCR assay for the simultaneous diagnosis of the 3 genotypes of interest of aMPV and IBV, followed by testing of 200 tracheal samples of vaccinated chickens with respiratory symptoms and finally a phylogenetic analysis of the sequences found. The assay detected up to 1 copy of each viral genome. The standard curves showed an efficiency between 90 and 100% in the multiplex assay and inter- and intra-assay coefficients of variation of 0.363 and 0.459, respectively and inter- and intraassay coefficients of variation of 0.363 and 0.459, respectively. 69.5% of samples were found positive alone or in coinfection. 114 samples were positive for IBV, 13 for aMPV-A and 25 for aMPV-B. RNA of aMPV-C was no detected. The most commonly found combination was aMPV-B and IBV within 6 samples, and the least common was aMPV-A and aMPV-B in coinfection in 2 samples. The assay was specific for amplification of the genomes of the studied respiratory viruses (IBV, aMPV-A, aMPV-B, aMPV-C) as no amplification was shown from other viral genomes (ChPV, CAstV, ANV, and FAdV) or from the negative controls. Partial genomic Sanger sequencing enabled to identify circulating vaccine-derived and wild-type strains of IBV and vaccine and vaccine-derived strains of aMPV-B. In conclusion, this newly developed multiplex RT-qPCR was shown to be able to detect individual infections as well as co-infections among the respiratory viruses investigated. It was demonstrated to be a reliable and efficient tool for rapidly and safely diagnosing these infections. Furthermore, this study represents the first report of aMPV strains in Ecuadorian poultry and demonstrates the circulation of aMPV-A, aMPV-B, and GI-13 IBV strains in unvaccinated chicken populations in the country. Thus, it highlights the importance of simultaneously identifying these pathogens in greater detail and on a regular basis in Ecuador. [ABSTRACT FROM AUTHOR]

The enormous effects of avian influenza on poultry production and the possible health risks to humans have drawn much attention to this disease. The H9N2 subtype of avian influenza virus is widely prevalent among poultry, posing a direct threat to humans through infection or by contributing internal genes to various zoonotic strains of avian influenza. Despite the widespread use of H9N2 subtype vaccines, outbreaks of the virus persist due to the rapid antigenic drift and shifts in the influenza virus. As a result, it is critical to develop a broader spectrum of H9N2 subtype avian influenza vaccines and evaluate their effectiveness. In this study, a recombinant baculovirus expressing the broad-spectrum HA protein was obtained via bioinformatics analysis and a baculovirus expression system (BES). This recombinant hemagglutinin (HA) protein displayed cross-reactivity to positive sera against several subbranch H9 subtype AIVs. An adjuvant and purified HA protein were then used to create an rHA vaccine candidate. Evaluation of the vaccine demonstrated that subcutaneous immunization of the neck with the rHA vaccine candidate stimulated a robust immune response, providing complete clinical protection against various H9N2 virus challenges. Additionally, virus shedding was more effectively inhibited by rHA than by the commercial vaccine. Thus, our findings illustrate the efficacy of the rHA vaccine candidate in shielding chickens against the H9N2 virus challenge, underscoring its potential as an alternative to conventional vaccines. [ABSTRACT FROM AUTHOR]

Avian pathogenic E. coli (APEC), a widespread bacterium, results in serious economic losses to the poultry industry annually, and it poses a threat to human health due to the contaminated retail poultry meat and eggs. Recently, it has been demonstrated that long non-coding RNAs played important roles in regulating gene expression and the animal immune response. This study aimed to systematically explore the function of the novel long intergenic non-coding transcript, lincRNA-73240, upon APEC infection. A bioinformatics analysis indicated that lincRNA-73240 had no coding ability and a relative stable secondary structure with multiple hairpin rings. Moreover, the RT-qPCR results showed that lincRNA-73240 was highly expressed in lungs, heart, liver, spleen, cecum tonsils, thymus, ileum, bursa of Fabricius, harderian gland, and muscles in comparison to the cerebrum. Additionally, overexpression of lincRNA-73240 can promote the expression levels of inflammation, apoptosis, autophagy, and oxidative stress-related genes, as well as the production of reactive oxygen species (ROS), malondialdehyde (MDA), and nitric oxide (NO) upon APEC infection, which lead to cellular injury and apoptosis. These findings collectively establish a foundation for the study of the biological function of chicken lincRNA-73240 and provide a theoretical basis for further research on the molecular mechanisms of the chicken immune response. [ABSTRACT FROM AUTHOR]

Background: Scavenging indigenous village chickens play a vital role in sub-Saharan Africa, sustaining the livelihood of millions of farmers. These chickens are exposed to vastly different environments and feeds compared to commercial chickens. In this study, we analysed the caecal microbiota of 243 Ethiopian village chickens living in different altitude-dependent agro-ecologies. Results: Differences in bacterial diversity were significantly correlated with differences in specific climate factors, topsoil characteristics, and supplemental diets provided by farmers. Microbiota clustered into three enterotypes, with one particularly enriched at high altitudes. We assembled 9977 taxonomically and functionally diverse metagenome-assembled genomes. The vast majority of these were not found in a dataset of previously published chicken microbes or in the Genome Taxonomy Database. Conclusions: The wide functional and taxonomic diversity of these microbes highlights their importance in the local adaptation of indigenous poultry, and the significant impacts of environmental factors on the microbiota argue for further discoveries in other agro-ecologies. EEwR8PKafK2-LVnkA2-YG- Video Abstract [ABSTRACT FROM AUTHOR]

Introduction: Laying performance is a key factor affecting production efficiency in poultry, but its molecular mechanism is still indistinct. In this study, Yaoshan chickens, a local breed in Guizhou, China, and merchant chickens (GYR) with higher egg yield after the three-line cross improvement hybridization of Yaoshan chickens were used as animal samples. Methods: To explore the regulatory mechanism of the diversities in laying performance, RNA-seq and ultra-performance liquid chromatographytandem mass spectrometry (UPLC--MS/MS) were used to describe the transcriptional and metabolic profiles of the ovaries of Yaoshan and GYR chickens. Results: At the transcriptional level, 288 differentially expressed genes were upregulated in Yaoshan chickens and 353 differentially expressed genes were upregulated in GYR chickens. In addition, GSEA showed that ECM-receptor interactions and the TGF-β signaling pathway were restrained, resulting in increased egg production in GYR chickens. Furthermore, the upregulation of thiamine and carnitine was identified by metabolomic analysis to facilitate the laying performance of hens. Finally, comprehensive analyses of the transcriptome and metabolome found that thiamine and carnitine were negatively correlated with ECM-receptor interactions and the TGF-β signaling pathway, which jointly regulate the laying performance of Yaoshan chickens and GYR chickens. Discussion: Taken together, our research delineates differences in the transcriptional and metabolic profiles of the ovaries of Yaoshan and GYR chickens during the peak egg production period and provides new hypotheses and clues for further research on poultry egg production performance and the improvement of economic benefits. [ABSTRACT FROM AUTHOR]

Proline is a functional essential amino acid for livestock and aquatic animals, which has physiological roles such as alleviating oxidative stress, participating in energy metabolism, regulating immunity, promoting protein synthesis and improving animal growth and reproductive performance. This paper describes the metabolic process, digestion and absorption of proline, and focuses on the nutritional physiological functions, research progress, and research outlook of proline to provide theoretical references for further research on the effects of proline nutrition on actual pig, chicken and aquatic animal. [ABSTRACT FROM AUTHOR]

Play is a widespread phenomenon in the animal kingdom with observations from all vertebrate classes. The adaptive value of this behaviour, however, remains unclear. In the past century, numerous theories have been put forward, ranging from releasing surplus energy to training species-specific behaviours. However, none of these theories can fully explain the functions of play. A recent neurocognitive theory suggests that play allows the brain to encounter many different and surprising situations that provide it with opportunities to learn about the environment and form predictions about it. This theory has, however, to our knowledge, previously not been experimentally tested. To start exploring the connection between play and cognition, we compared the cognitive capacities of White Leghorn chicks that were stimulated to play in the first five weeks of their lives with chicks that did not receive any play stimulation. More specifically, we wanted to test the connection between specific types of play and cognitive domains. To achieve this, we designed two play treatments: object players that were provided with a variety of toys during their treatment, and social players that were released into an arena with plenty of space and conspecifics, as this has previously been shown to trigger social play. Subsequently, all three treatments (control, object players, social players) were tested in a cognitive test battery consisting of two experiments targeting the social domain and two targeting the physical domain. We found no improvement of cognitive capacities in either play treatment group compared to control subjects, though the social play treatment appears to have affected some behavioural variables recorded during the cognitive tests. Chicks that had played socially were in general bolder, more explorative and had more access to resources in the tests. This might subsequently allow them to exploit their environment more efficiently, which could in turn affect their welfare as they might be more resilient to stress and have more access to resources. More studies will be needed to assess the longterm effects of play on cognitive capacities and welfare of chickens. [ABSTRACT FROM AUTHOR]

This study aims to determine the percentage of chicken meat in beef and chicken mixtures, which is the most common form of beef adulteration. Ground beef and beef sausages were prepared with mixtures containing chicken meat, ranging from 0.0% to 100.0% with 5.0% increments, and analyzed using a near-infrared spectroscopy device. Optimal analysis conditions were determined through the examination of a wide range of regression models. The best regression model for ground beef mixtures yielded the following results: RMSEC (Root Mean Square Error of Calibration): 2.35, RMSEV (Root Mean Square Error of Validation): 3.36, R²C (R-Value Calibration): 0.99, R2V (R-Value Validation): 0.98. The results for beef sausages were as follows: RMSEC: 2.56, RMSEV: 3.66, R²C: 0.99, R2V: 0.98. As a result, the chicken meat content in beef mixtures was detected with a margin of error of 2.05%, while the chicken meat content in beef sausages was detected with a margin of error of 2.12%. [ABSTRACT FROM AUTHOR]

Marek's disease (MD), caused by the Marek's disease virus, is a lymphoproliferative disease in chickens that can be controlled by vaccination. However, the current vaccines can limit tumor growth and death but not virus replication and transmission. The present study aimed to evaluate host responses following intramuscular injection of an mRNA vaccine encoding gB and pp38 proteins of the MDV within the first 36 h. The vaccine was injected in low and high doses using prime and prime-boost strategies. The expression of type I and II interferons (IFNs), a panel of interferon-stimulated genes, and two key antiviral cytokines, IL-1β and IL-2, were measured in spleen and lungs after vaccination. The transcriptional analysis of the above genes showed significant increases in the expression of MDA5, Myd88, IFN-α, IFN-β, IFN-γ, IRF7, OAS, Mx1, and IL-2 in both the spleen and lungs within the first 36 h of immunization. Secondary immunization increased expression of all the above genes in the lungs. In contrast, only IFN-γ, MDA5, MyD88, Mx1, and OAS showed significant upregulation in the spleen after the secondary immunization. This study shows that two doses of the MDV mRNA vaccine encoding gB and pp38 antigens activate innate and adaptive responses and induce an antiviral state in chickens. [ABSTRACT FROM AUTHOR]

To investigate the mechanism by which Ganoderma lucidum enhances the immune function in chickens, genes related to chicken immune function and the main effective components of Ganoderma lucidum targets were obtained through databases such as TCMSP. Visualization analysis of the Ganoderma lucidum-target-immune protein-protein interaction (PPI) network was performed using Cytoscape 3.10.0 software, followed by GO and KEGG pathway enrichment analysis through the David database. Finally, molecular docking was conducted using AutoDock software to verify the binding activity of key effective components with key targets. The results showed that a total of 42 effective components of Ganoderma were identified, including 10 key effective components such as Ganoderma lucidum alcohol B, Ganoderma spore lactone B, and Ganoderma lucidum aldehyde B, along with 332 immune-related genes. The PPI network included seven key targets such as Interleukin-6 (IL-6), Interleukin-1 beta (IL-1β), and non-receptor tyrosine kinase (SRC). The GO functional enrichment analysis covered 23 biological processes, 22 cellular components, and 23 molecular functions. The KEGG pathway enrichment analysis yielded 11 related signaling pathways. The minimum binding energy of the molecular docking was all less than -20.9 kJ/mol, indicating good docking results. The study suggests that the key effective components of Ganoderma that enhance chicken immune function are 10, the key targets are 7, and the related signaling pathways are 11, the results can provide a reference for the application of Ganoderma as a feed additive. [ABSTRACT FROM AUTHOR]

An experimental study was performed to evaluate the responses of broiler chickens to dietary substitution of barley for corn. A total of 252 one-day-old broiler chicks were randomly distributed among 18 floor pens. Six such pens were then randomly assigned to each dietary treatment. Dietary treatments consisted of a corn-based diet, a barley-based diet, and the barley-based diet plus an enzyme mixture. Results indicated that barley substitution for corn significantly (p< 0.0001) impacted broiler performance criteria. However, enzyme supplementation significantly (p= 0.02) improved the feed conversion ratio to the extent obtained in the corn control. The villus absorptive surface area was shrunk in birds fed a barley diet compared to the corn diet. Nevertheless, supplementation of the barley diet with the enzyme mixture significantly (p= 0.02) restored the situation. The expression of the TLR2 gene was significantly down-regulated by replacing barley with corn. Enzyme supplementation of the barley diet significantly (p< 0. 001) up-regulated TLR2 gene expression but not to the extent observed in the corn control group. Significant increases were observed in circulatory levels of uric acid (p< 0.05), total protein (p<0.01), and albumin (p< 0.001) when barley was substituted for corn. Enzyme supplements did not make any significant difference to these variables. In conclusion, the substitution of barley for corn was associated with the poor performance of broilers. However, supplementing barley-based diets with the enzyme mixture improved chicken's performance through enhanced villus absorptive surface area. It reduced the turnover of enterocytes, as reflected in a lower crypt depth in the jejunum. [ABSTRACT FROM AUTHOR]

Primordial germ cells (PGCs) are the precursors of germ cells and play a crucial role in germline transmission. In chickens, PGCs can be cultured in vitro while maintaining their germline stem cell characteristics. The Deleted in Azoospermia-Like (DAZL) gene, which is highly expressed in PGCs, is essential for germ cell development. Here, through gene knockout experiments, we discovered that the loss of DAZL expression in chicken PGCs led to decreased proliferation and survival. By next employed techniques such as RIP-seq (RNA Binding Protein Immunoprecipitation) and Co-IP-MS/MS (Co-immunoprecipitation Mass Spectrometry), we identified genes directly regulated by DAZL or cooperating with DAZL at the transcriptomic and proteomic levels. DAZL was found to control genes related to germline development, pluripotency, and cell proliferation in PGCs. Additionally, we observed a significant overlap between RNAs and proteins that interact with both DAZL and DDX4, indicating their cooperation in the gene regulation network in chicken PGCs. Our research provides valuable insights into the function of the DAZL gene in germline cells. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To evaluate the topical antiseptic activity of saline, chlorhexidine (CHX), and povidone-iodine (PI) scrubs on the skin of chickens with or without the addition of DuraPrep (DP). ANIMALS: 7 healthy adult Orpington hens (Gallus gallus domesticus). METHODS: The right apterium corporale laterale was swabbed for standard aerobic bacterial culture and colony-forming unit (CFU) determination. The apterium was divided into 3 areas and treated with sterile saline, CHX, or PI. Samples were collected by swabbing each area before and after additional treatment with DP. CFU's were counted after 48 hours of incubation. Statistical analysis was performed using a linear mixed model with a continuous outcome. RESULTS: Compared to saline, CHX and PI treatment without DP decreased CFU count by 119 (95% CI, 55 to 183; P < .001) and 123 (95% CI, 58 to 187; P < .001), respectively. The application of DP after CHX and PI further decreased CFU counts by 6 (P = .01) and 9 (P = .01), respectively. DP after saline treatment decreased counts by 128 CFU (95% CI, 63 to 192; P < .001). No significant difference was detected between saline, PI, or CHX after DP application (-1.0 CFU; 95% CI, 63.4 to -65.4; P = .98 for both PI and CHX). CLINICAL RELEVANCE: CHX or PI provided greater reductions in bacterial CFU than saline, and all combinations with DP provided similar results. No notable cutaneous reactions were detected at any point. This data suggests that a scrub protocol including CHX or PI with DP is acceptable in surgical site preparation of chickens. [ABSTRACT FROM AUTHOR]

Body weight is an economically important trait in poultry that shows sexual dimorphism (SD). In the present study, variation in SD in Mazandaran native chickens was investigated in terms of the (Co) variance components and genetic parameters of body weight between males and females. Studied traits were body weights at hatch (BW1), 8 weeks (BW8) and 12 weeks of age (BW12). Also, for weight at sexual maturity (WSM) covariance components were only estimated in females. Cross‐sex direct and maternal correlations were also estimated for studied traits except for WSM. For this purpose, a deep 21‐generation pedigree and body weight data (57,576 BW1, 72,925 BW8, 62,727 BW12 and, 42,496 WSM) were used. Evaluation of SD of body weight was performed using six bivariate animal models with and without considering the genetic and permanent maternal environmental effects under the restricted maximum likelihood method in WOMBAT software. Model with direct additive genetic effects and maternal genetic effects without covariance between them was identified as the best model for BW1 and BW8. The Model including direct additive genetic effects and permanent maternal environmental effects was the best model for BW12 and WSM. Direct heritability (h2) estimates for BW1, BW8 and, BW12 were, respectively, 0.05 ± 0.013, 0.17 ± 0.02 and, 0.25 ± 0.03 in males and, 0.05 ± 0.012, 0.15 ± 0.01 and 0.21 ± 0.01 in females. Also, the direct heritability of WSM based on univariate analysis in females was estimated to be 0.40 ± 0.01. Maternal heritability (hm2) varied from 0.39 ± 0.01 (BW1) to 0.04 ± 0.009 (BW8) in males, and 0.36 ± 0.10 (BW1) to 0.04 ± 0.006 (BW8) in females. The correlation between direct genetic effects between males and females for BW1 was not significantly different from one. The direct genetic correlation between the two sexes for BW8 and BW12 was significantly different from 1 concluding that these traits are dimorphic in terms of direct genetic effects and therefore independent selection in both sexes is possible. [ABSTRACT FROM AUTHOR]

The identification of accurate gene insertion sites on chicken sex chromosomes is crucial for advancing sex control breeding materials. In this study, the intergenic region NC_006127.4 on the chicken Z chromosome and the non-repetitive sequence EE0.6 on the W chromosome were selected as potential gene insertion sites. Gene knockout vectors targeting these sites were constructed and transfected into DF-1 cells. T7E1 enzyme cleavage and luciferase reporter enzyme analyses revealed knockout efficiencies of 80.00% (16/20), 75.00% (15/20), and 75.00% (15/20) for the three sgRNAs targeting the EE0.6 site. For the three sgRNAs targeting the NC_006127.4 site, knockout efficiencies were 70.00% (14/20), 60.00% (12/20), and 45.00% (9/20). Gel electrophoresis and high-throughput sequencing were performed to detect potential off-target effects, showing no significant off-target effects for the knockout vectors at the two sites. EdU and CCK-8 proliferation assays revealed no significant difference in cell proliferation activity between the knockout and control groups. These results demonstrate that the EE0.6 and NC_006127.4 sites can serve as gene insertion sites on chicken sex chromosomes for gene editing without affecting normal cell proliferation. [ABSTRACT FROM AUTHOR]

As an RNA binding protein (RBP), DDX5 is widely involved in the regulation of various biological activities. While recent studies have confirmed that DDX5 can act as a transcriptional cofactor that is involved in the formation of gametes, few studies have investigated whether DDX5 can be used as a transcription factor to regulate the formation of primordial germ cells (PGCs). In this study, we found that DDX5 was significantly up-regulated during chicken PGC formation. Under different PGC induction models, the overexpression of DDX5 not only up-regulates PGC markers but also significantly improves the formation efficiency of primordial germ cell-like cells (PGCLC). Conversely, the inhibition of DDX5 expression can significantly inhibit both the expression of PGC markers and PGCLC formation efficiency. The effect of DDX5 on PGC formation in vivo was consistent with that seen in vitro. Interestingly, DDX5 not only participates in the formation of PGCs but also positively regulates their migration and proliferation. In the process of studying the mechanism by which DDX5 regulates PGC formation, we found that DDX5 acts as a transcription factor to bind to the promoter region of BMP4—a key gene for PGC formation—and activates the expression of BMP4. In summary, we confirm that DDX5 can act as a positive transcription factor to regulate the formation of PGCs in chickens. The obtained results not only enhance our understanding of the way in which DDX5 regulates the development of germ cells but also provide a new target for systematically optimizing the culture and induction system of PGCs in chickens in vitro. [ABSTRACT FROM AUTHOR]