Honeycomb Enhances the Egg-Laying Capacity of Laying Hens by Modulating Ovarian Function and Yolk Precursor Synthesis

This study assessed the effects of dietary honeycomb supplementation on laying performance, intestinal inflammation, ovarian function, and yolk precursor synthesis in laying hens. A total of 320 Dawu Golden Phoenix laying hens (288-d-old) were randomly assigned into four treatment groups with eight replicates of 10 hens each. Hens were provided diets containing 0, 0.5, 1.0, or 2.0 g/kg honeycomb for 30 d. Dietary honeycomb significantly increased average egg weight, average daily feed intake, and laying rate, while decreasing the feed conversion ratio (p < 0.05). It enhanced serum antioxidant capacity, as reflected by higher GSH, SOD, and CAT activity (p < 0.05). Meanwhile, honeycomb modulated the expression of Nrf2/Keap1 pathway-related genes, accompanied by increased expression of downstream antioxidant-related genes. Additionally, honeycomb downregulated intestinal inflammatory- and apoptosis-related factors (p < 0.05), which effectively alleviated intestinal inflammation responses. In the liver, honeycomb showed favorable histological changes, including fewer lipid droplets and less vacuolar degeneration. Furthermore, it decreased serum ALT, AST, and TG levels and promoted yolk precursor synthesis by upregulating genes associated with lipid transport and vitellogenesis (p < 0.05). In the ovary, honeycomb optimized ovarian morphology and follicle development; elevated serum FSH, E2, and MLT levels; and enhanced the expression of steroidogenesis-related genes (p < 0.05), thereby promoting steroid hormone synthesis and reducing follicular atresia. In conclusion, dietary honeycomb supplementation could maintain intestinal health, modulate hepatic and ovarian metabolism functions, promote yolk precursor synthesis, improve follicle development, and consequently, enhance the laying performance of hens.