MiRNAs have been found to be involved in the regulation of ovarian function as important post-transcriptional regulators, including regulators of follicular development, steroidogenesis, cell atresia, and even the development of ovarian cancer. In this study, we evaluated the regulatory role of gga-miR-449b-5p in follicular growth and steroid synthesis in ovarian granulosa cells (GCs) of laying hens through qRT-PCR, ELISAs, western blotting and dual-luciferase reporter assays, which have been described in our previous study. We demonstrated that gga-miR-449b-5p was widely expressed in granulosa and theca layers of the different-sized follicles, especially in the granulosa layer. The gga-miR-449b-5p had no significant effect on the proliferation of GCs, but could significantly regulate the expression of key steroidogenesis-related genes (StAR and CYP19A1) (p < 0.01) and the secretion of P4 and E2 (p < 0.01 and p < 0.05). Further research showed that gga-miR-449b-5p could target IGF2BP3 and downregulate the mRNA and protein expression of IGF2BP3 (p < 0.05). Therefore, this study suggests that gga-miR-449b-5p is a potent regulator of the synthesis of steroid hormones in GCs by targeting the expression of IGF2BP3 and may contribute to a better understanding of the role of functional miRNAs in laying hen ovarian development.

This study investigated the effects of dietary supplementation with Vitamin E (VE) and selenium (Se) on immunostressed broilers. In the experiment, a total of 576 Gushi chickens were randomly allocated into 12 groups. They were respectively fed diets with different levels of VE and Se. Lipopolysaccharide (LPS) immune treatment was administered at 23, 25, and 27 days of age. At 28 days of age, the antioxidant indicators and immune factors in their serum, liver, and intestine were measured. The results indicated that (1) LPS treatment significantly elevated the contents of nitric oxide (NO) and nitric oxide synthase (NOS) in the duodenum and jejunum (p < 0.01). Conversely, adding VE and Se to the diet of LPS-treated chicks could significantly decrease the content of NO in the duodenum and the activities of NOS in the duodenum and jejunum (p < 0.01). (2) LPS treatment significantly decreased the content of malondialdehyde (MDA) in the liver of broilers, glutathione peroxidase (GSH-Px), and the activities of serum superoxide dismutase (SOD) (p < 0.01). Dietary supplementation of selenium could significantly reduce the content of MDA (p < 0.01), and the treatment groups with 200 mg/kg VE and 0.6 mg/kg Se exhibited the most favorable effects. (3) Adding Se or VE to the diet of LPS-treated chicks could significantly increase the thymus index and spleen index (p < 0.05) and significantly decrease the bursa of Fabricius index (p < 0.05). Among them, the thymus index was the highest in the 100 mg/kg VE group, and the interaction of the three factors had a significant influence on the thymus index and bursa of Fabricius index (p < 0.05). (4) The level ofinterleukin-6 (IL-6) in the serum of broilers in the LPS treatment group was significantly increased. However, selenium and Vitamin E were added to the diet of LPS-treated chicks to reduce the contents of serum IL-6 and IL-8, as well as adrenocorticotropic hormone (ACTH) and tumor necrosis factor-α (TNF-α). Moreover, the interaction of the three factors has a significant impact on immune indicators (p < 0.01). In conclusion, adding 100–200 mg/kg of VE and 0.6 mg/kg of Se to the diet of broiler chickens has certain advantages in enhancing immunity and antioxidant capacity.

Adiponectin, an adipocyte-derived adipokine, plays a key regulatory role in physiological processes such as energy balance, glucose metabolism, and fatty acid oxidation. Evidence from animal studies indicates that adiponectin is involved in the regulation of reproductive performance by mediating molecular crosstalk between energy metabolism and the reproductive system. As the core regulatory center for animal reproduction, the hypothalamic–pituitary–gonadal (HPG) axis exhibits a close link between its functional state and the body’s energy homeostasis. This review systematically summarizes the expression patterns and molecular mechanisms of adiponectin and its receptors at different levels of the animal HPG axis. It provides a theoretical basis for future research and applications of adiponectin in animal reproduction.

The aim of this study was to develop a dynamic factorial model for predicting amino acid requirements in Hy-Line Gray laying hens during critical early growth stages (0–84 days), addressing the need for precision feeding in modern poultry production systems. Methods: Four sequential trials were conducted. In Trial 1, growth curves and protein deposition equations were developed based on fortnightly body composition analyses, with parameters evaluated using the Akaike and Bayesian information criteria (AIC and BIC). In Trial 2, the carcass and feather amino acid profiles were characterized via HPLC. And established the amino acid composition patterns of chicken feather protein and carcass protein (AAF and AAC). In Trial 3, maintenance requirements were quantified through nitrogen balance studies, and in Trial 4, amino acid patterns of feather protein (APD) and apparent protein digestibility (ADD) were established using an endogenous indicator method. These datasets were integrated through factorial modeling to predict age-specific nutrient demands. Results: The developed model revealed the following quantitative requirements (g/day) for 18 amino acids across developmental stages: aspartic acid (0.1–0.863), glutamic acid (0.170–1.503), serine (0.143–0.806), arginine (0.165–0.891), glycine (0.258–1.279), threonine (0.095–0.507), proline (0.253–1.207), alanine (0.131–0.718), valine (0.144–0.737), methionine (0.023–0.124), cysteine (0.102–0.682), isoleucine (0.086–0.458), leucine (0.209–1.067), phenylalanine (0.086–0.464), histidine (0.024–0.133), lysine (0.080–0.462), tyrosine (0.050–0.283), and tryptophan (0.011–0.060). The model demonstrated strong predictive validity throughout the 12-week growth period. Conclusion: This integrative approach yielded the first dynamic requirement model for Hy-Line Gray layers during early development. The factorial framework enables precise adjustment of amino acid provisions to match changing physiological needs and has high potential value in optimizing feed efficiency and supporting sustainable layer production practices.