In modern animal husbandry, stress can be viewed as an automatic response triggered by exposure to adverse environmental conditions. This response can range from mild discomfort to severe consequences, including mortality. The poultry industry, which significantly contributes to human nutrition, is not exempt from this issue. Although genetic selection has been employed for several decades to enhance production output, it has also resulted in poor stress resilience. Stress is manifested through a series of physiological reactions, such as the identification of the stressful stimulus, activation of the sympathetic nervous system and the adrenal medulla, and subsequent hormonal cascades. While brief periods of stress can be tolerated, prolonged exposure can have more severe consequences. For instance, extreme fluctuations in environmental temperature can lead to the accumulation of reactive oxygen species, impairment of reproductive performance, and reduced immunity. In addition, excessive noise in poultry slaughterhouses has been linked to altered bird behaviour and decreased production efficiency. Mechanical vibrations have also been shown to negatively impact the meat quality of broilers during transport as well as the egg quality and hatchability in hatcheries. Lastly, egg production is heavily influenced by light intensity and regimens, and inadequate light management can result in deficiencies, including visual anomalies, skeletal deformities, and circulatory problems. Although there is a growing body of evidence demonstrating the impact of environmental stressors on poultry physiology, there is a disproportionate representation of stressors in research. Recent studies have been focused on chronic heat stress, reflecting the current interest of the scientific community in climate change. Therefore, this review aims to highlight the major abiotic stressors in poultry production and elucidate their underlying mechanisms, addressing the need for a more comprehensive understanding of stress in diverse environmental contexts.

Chicken embryos serve as an important model for investigating germ cells due to their ease of accessibility and manipulation within the egg. Understanding the development of germ cells is particularly crucial, as they are the only cell types capable of transmitting genetic information to the next generation. Therefore, gene expression regulation in germ cells is important for genomic function. Epigenetic programming is a crucial biological process for the regulation of gene expression without altering the genome sequence. Although epigenetic programming is evolutionarily conserved, several differences between chickens and mammals have been revealed. In this review, we compared the epigenetic regulation of germ cells in chickens and mammals (mainly mice as a representative species). In mammals, migrating primordial germ cells (precursors for germ cells [PGCs]) undergo global DNA demethylation and persist until sexual differentiation, while in chickens, DNA is demethylated until reaching the gonad but remethylated when sexually differentiated. Prospermatogonia is methylated at the onset of mitotic arrest in mammals, while DNA is demethylated at mitotic arrest in chickens. Furthermore, genomic imprinting and inactivation of sex chromosomes are differentially regulated through DNA methylation in chickens and mammals. Chickens and mammals exhibit different patterns of histone modifications during germ cell development, and non-coding RNA, which is not involved in PGC differentiation in mice, plays an important role in chicken PGC development. Additionally, several chicken-specific non-coding RNAs have been identified. In conclusion, we summarized current knowledge of epigenetic gene regulation of chicken germ cells, comparing that of mammals, and highlighted notable differences between them.

Omics approaches have significantly contributed to our understanding of several aspects of chicken reproduction. This review paper gives an overview of the use of omics technologies such as genomics, transcriptomics, proteomics, and metabolomics to elucidate the mechanisms of chicken reproduction. Genomics has transformed the study of chicken reproduction by allowing the examination of the full genetic makeup of chickens, resulting in the discovery of genes associated with reproductive features and disorders. Transcriptomics has provided insights into the gene expression patterns and regulatory mechanisms involved in reproductive processes, allowing for a better knowledge of developmental stages and hormone regulation. Furthermore, proteomics has made it easier to identify and quantify the proteins involved in reproductive physiology to better understand the molecular mechanisms driving fertility, embryonic development, and egg quality. Metabolomics has emerged as a useful technique for understanding the metabolic pathways and biomarkers linked to reproductive performance, providing vital insights for enhancing breeding tactics and reproductive health. The integration of omics data has resulted in the identification of critical molecular pathways and biomarkers linked with chicken reproductive features, providing the opportunity for targeted genetic selection and improved reproductive management approaches. Furthermore, omics technologies have helped to create biomarkers for fertility and embryonic viability, providing the poultry sector with tools for effective breeding and reproductive health management. Finally, omics technologies have greatly improved our understanding of chicken reproduction by revealing the molecular complexities that underpin reproductive processes.

The coronavirus has wreaked havoc on the global economy before the eyes of the entire world. Due to evolving consumer needs and expectations during the pandemic, the supply and demand for various goods and services varied from the pre-COVID-19 period. This article aims to understand the changes in purchasing and food choices, focusing particularly on meat and meat products, made by consumers and households in response to the crisis caused by the COVID-19 pandemic. The study also indicates the impact directions of these changes and assesses the magnitude of the contribution of various determinants that influenced them. The literature review from 2020 to 2023 was conducted using Scopus and the Web of Science scientific databases. The study identified sociodemographic and individual factors as the main determinants influencing consumers\' purchasing or eating behavior. Positive shifts (e.g., implementing strategies to better manage food at home through activities like creating shopping lists, the average increase in consumer spending during store visits, and decrease in visit frequencies) or negative changes (e.g., shortages of food products in stores due to consumer panic buying, unusually high demand resulting from stockpiling, purchasing fewer fresh products, increased consumption of unhealthy foods and snacking, among other factors) during isolation were influenced by various individual factors (e.g., motivation, mental state) or sociodemographic factors (e.g., gender, age, income level, education). While individual factors had a greater impact on changes in consumer behavior in the early stages of the COVID-19 pandemic, socio-demographic factors became more important as the pandemic progressed.

The rapid population growth in Africa is associated with an increasing demand for livestock products which in turn can lead to antimicrobial use. Antimicrobial usage in animals contributes to the emergence and selection of resistant bacteria which constitutes a serious public health threat. This study aims to review and summarize the available information on highest priority critically important antimicrobials (HPCIAs) resistance in livestock production in Africa. This work will help to inform future policies for controlling antimicrobial resistance (AMR) in the food production chain. A scoping review was conducted according to the Cochrane handbook and following PRISMA 2020 guidelines for reporting. Primary research studies published after 1999 and reporting resistance of Escherichia coli, Enterococcus spp, Staphylococcus aureus, Salmonella spp, and Campylobacter spp to HPCIAs in poultry, cattle, pigs, goats, and sheep in Africa were searched in four databases. A total of 312 articles were included in the review. The majority of the studies (40.7) were conducted in North African countries. More than 49.0% of included studies involved poultry and 26.2% cattle. Cephalosporins and quinolones were the most studied antimicrobial classes. Of the bacteria investigated in the current review, E. coli (41.7%) and Salmonella spp (24.9%) represented the most commonly studied. High levels of resistance against erythromycin in E. coli were found in poultry (MR 96.1%, IQR 83.3-100.0%), cattle (MR 85.7%, IQR 69.2-100.0%), and pigs (MR 94.0%, IQR 86.2-94.0%). In sheep, a high level of resistance was observed in E. coli against nalidixic acid (MR 87.5%, IQR 81.3-93.8%). In goats, the low level of sensibility was noted in S. aureus against streptomycin (MR 86.8%, IQR 19.4-99.0%). The study provides valuable information on HPCIAs resistance in livestock production in Africa and highlights the need for further research and policies to address the public health risk of AMR. This will likely require an investment in diagnostic infrastructure across the continent. Awareness on the harmful impact of AMR in African countries is a requirement to produce more effective and sustainable measures to curb AMR.

Heat stress is a major environmental threat to poultry production systems, especially in tropical areas. The effects of heat stress have been discovered in several areas, including reduced growth rate, reduced egg production, low feed efficiency, impaired immunological responses, changes in intestinal microflora, metabolic changes, and deterioration of meat quality. Although several methods have been used to address the heat stress problem, it persists. The answer to this problem can be remedied sustainably if genetic improvement approaches are available. Therefore, the purpose of this review article was to present the application of different approaches to genetic improvement in poultry in the hope that users will find suitable solutions for their poultry population and be able to plan future poultry breeding programs.

Poultry meats, in particular chicken, have high rates of consumption globally. Poultry is the most consumed type of meat in the United States (US), with chicken being the most common type of poultry consumed. The amounts of chicken and total poultry consumed in the US have more than tripled over the last six decades. This narrative review describes nutritional profiles of commonly consumed chicken/poultry products, consumption trends, and dietary recommendations in the US. Overviews of the scientific literature pertaining to associations between, and effects of consuming chicken/poultry on, body weight and body composition, cardiovascular disease (CVD), and type II diabetes mellitus (T2DM) are provided. Limited evidence from randomized controlled trials indicates the consumption of lean unprocessed chicken as a primary dietary protein source has either beneficial or neutral effects on body weight and body composition and risk factors for CVD and T2DM. Apparently, zero randomized controlled feeding trials have specifically assessed the effects of consuming processed chicken/poultry on these health outcomes. Evidence from observational studies is less consistent, likely due to confounding factors such as a lack of a description of and distinctions among types of chicken/poultry products, amounts consumed, and cooking and preservation methods. New experimental and observational research on the impacts of consuming chicken/poultry, especially processed versions, on cardiometabolic health is sorely needed.

The inclusion of Moringa oleifera leaf meal (MLM) in chicken diets especially in developing countries is on the increase due to scarcity of traditional feedstuffs. Therefore, this investigation aimed to explore the effects of MLM on lipid profiles and production characteristics of laying hens. Twenty-three publications retrieved from Web of Science, PubMed, Scopus and Google Scholar search engines were used for the analysis. Data from the 23 studies were analysed using random-effects model in OpenMEE software. Results were presented as standardised mean difference (SMD) at a 95% confidence interval. The results show significant improvement in feed conversion ratio (SMD =  - 0.49; p < .001), egg mass (SMD = 0.35; p = .003), Haugh unit (SMD = 0.39; p < .001), eggshell thickness (SMD = 0.63; p < .001) and eggshell weight (SMD = 0.45; p < .001) at a reduced feed intake. On the other hand, egg weight, hen-day egg production and blood high-density lipoprotein cholesterol were not statistically different from controls. Results reveal that dietary MLM enhanced blood cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides and yolk cholesterol concentrations in laying hens. There is presence of significant heterogeneity and meta-regression revealed that study country, number of hen, housing system, hen age, inclusion level and layer strains were predictors of the treatment effect. In conclusion, the results of this meta-analysis suggest that inclusion of MLM in the diet of laying hens improved feed conversion ratio, aspects of egg quality and blood/yolk cholesterol concentrations in laying hens at a reduced feed intake.

Chicken is a major source of protein for the increasing human population and is useful for research purposes. There are almost 1,600 distinct regional breeds of chicken across the globe, among which a large body of genetic and phenotypic variations has been accumulated due to extensive natural and artificial selection. Moreover, natural selection is a crucial force for animal domestication. Several approaches have been adopted to detect selection signatures in different breeds of chicken using whole genome sequencing (WGS) data including integrated haplotype score (iHS), cross-populated extend haplotype homozygosity test (XP-EHH), fixation index (FST), cross-population composite likelihood ratio (XP-CLR), nucleotide diversity (Pi), and others. In addition, gene enrichment analyses are utilized to determine KEGG pathways and gene ontology (GO) terms related to traits of interest in chicken. Herein, we review different studies that have adopted diverse approaches to detect selection signatures in different breeds of chicken. This review systematically summarizes different findings on selection signatures and related candidate genes in chickens. Future studies could combine different selection signatures approaches to strengthen the quality of the results thereby providing more affirmative inference. This would further aid in deciphering the importance of selection in chicken conservation for the increasing human population.

This scoping review was conducted to systematically search and chronicle scientific literature pertinent to poultry intake and human health. The protocol (uploaded to Open Science Framework, https://osf.io/2k7bj/) was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews guidelines. Articles with observational and experimental research, narrative and systematic reviews, and meta-analyses were included. Among 13,141 articles identified, 525 met inclusion criteria. Among these 525 articles, 212 focused on cancer morbidity and mortality; 41 on cardiovascular disease (CVD) morbidity and mortality; 52 on CVD risk factors; 32 on type 2 diabetes mellitus (T2DM) morbidity and mortality; 33 on T2DM risk factors; and 42 on body weight and body composition. An \"Other\" category (181 articles) included nutrient status, psychological well-being/mental health, cognition, microbiome, chronic kidney disease, nonalcoholic fatty liver disease, skin disorders, and fertility, among others. Among the 525 included articles, 366 were observational, 64 were experimental, and 76 were reviews and meta-analyses. Eighty-three percent of articles focused on adults or older adults. A paucity of research exists to support poultry as health-promoting foods, with most research only indirectly assessing poultry intake compared with other foods of interest (e.g., red meats or plant-based protein foods). No randomized controlled trials and only 1% of OBS assessed the influence of processed poultry intake on human health. In the future, the relative health effects of consuming poultry will be compared with a widening array of traditional and new protein-rich food products, necessitating the need for research to assess poultry as foods of choice. Science and health professionals, the poultry industry, and the public will benefit from new observational and experimental research to address cutting-edge scientific, public policy, and consumer topics pertinent to poultry intake and human health.