Reproductive failure associated with aging is a well-known phenomenon. However, the mechanism by which this failure occurs in broiler breeder roosters is still unclear. A previous study conducted in our laboratory, comparing young and aging broiler breeder roosters, demonstrated an elevation in hypothalamic vasoactive intestinal peptide (VIP) and pituitary prolactin (PRL) gene expression accompanied by a deterioration of gonadal axis function. This resulted in a decrease in semen-quality variables as roosters aged. The objective of this study was to examine the involvement of the serotonergic axis in the age-associated reproductive failure in broiler breeder roosters. Cobb roosters aged 64 wk were divided into 3 groups (n = 20 each): parachlorophenylalanine (PCPA) administration, active immunization against chicken VIP, and controls. At 69 wk of age, each group was divided into 2 equal subgroups: 1 received ovine PRL and the other served as controls. Weekly semen volume, concentration and motility, and plasma testosterone, estradiol, and PRL concentrations were examined. At the end of the experiment, roosters were euthanized, testes were weighed, and hypothalamus and pituitary were removed to assay the expression of genes encoding hypothalamic GnRH-I, pituitary FSH, pituitary LH, hypothalamic VIP, and pituitary PRL. Both PCPA administration and active immunization against chicken VIP significantly increased testis weight, semen volume, sperm concentration, ejaculation grade, plasma testosterone level, and GnRH-I, FSH and LH gene expression compared with controls (P ≤ 0.05). In addition, a decrease in plasma estradiol and PRL concentrations and VIP and PRL gene expression was observed in PCPA- and VIP-immunized birds compared with controls (P ≤ 0.05). Administration of PRL in all groups decreased gonadal axis function and semen-quality variables (P ≤ 0.05). Collectively, these results suggest that the increasing expression levels of the serotonergic axis in aging broiler breeder roosters inhibit proper gonadal function and reproductive performance. This article establishes for the first time the inhibitory role of serotonin on reproduction in aging roosters.
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http://dx.doi.org/10.1016/j.domaniend.2015.04.001 | DOI Listing |
Poult Sci
December 2024
Department of Poultry Science, University of Georgia, Athens, GA 30602-2772, USA.
Semen cryopreservation is essential for preserving genetic resources and enabling artificial insemination in poultry breeding. However, avian sperm is known to experience detrimental changes during the freezing process. Telmisartan, an angiotensin-II receptor antagonist recognized for its antioxidant properties and ability to activate AMP-activated protein kinase (AMPK), was hypothesized to improve post-thaw semen quality by enhancing mitochondrial function and providing antioxidant protection to sperm.
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December 2024
Departments of Animal and Food Sciences, Biological Sciences, Medical and Molecular Sciences, and Microbiology Graduate Program, University of Delaware, Newark, DE, USA.
The transcriptional regulation of gene expression in the latter stages of follicular development in laying hen ovarian follicles is not well understood. Although differentially expressed genes (DEGs) have been identified in pre-recruitment and pre-ovulatory stages, the master regulators driving these DEGs remain unknown. This study addresses this knowledge gap by utilizing Master Regulator Analysis (MRA) combined with the Algorithm for the Reconstruction of Accurate Cellular Networks (ARACNe) for the first time in laying hen research to identify master regulators that are controlling DEGs in pre-recruitment and pre-ovulatory phases.
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December 2024
Department of Pathology, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh. Electronic address:
Respiratory viral infections have a considerable detrimental impact on animal health as well as significant financial consequences in the poultry industry. The primary aim of this study is to investigate the major pathogens involved in respiratory diseases of poultry, the co-infection rate, and their epidemiological distribution in commercial chicken farms in Bangladesh. From June 2022 to December 2023, 300 pooled samples (swabs from live birds, and respiratory tissues from dead birds) were collected from the selected poultry farms where respiratory outbreaks were noticed.
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October 2024
Department of Poultry Science, Mississippi State University, Starkville, MS 39759, USA. Electronic address:
The broiler breeder industry is facing a problem with fertility, hatchability, and the number of broiler breeder eggs produced per hen. The supplementation of trace minerals such as zinc, manganese, and copper in broiler breeder diets has been previously linked to an increase in eggshell quality, which may lead to increased fertility, hatchability, and chick quality. The objective of this study was to explore the effect of amino-acid complexed mineral supplementation on eggshell quality, fertility, hatchability, chick quality, and shell translucency.
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November 2024
Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agricultural, Food, and Environmental Sciences, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel. Electronic address:
Hatchability rates in broilers pose a significant challenge in the poultry industry. Despite advancements in breeding and incubation technology, hatch rates remain suboptimal due to factors like genetics, egg management, environmental stress, nutrition, and breeder age. Understanding the mechanisms behind compromised hatchability is crucial for improving broiler production.
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