Comprehensive study on the impact of ginger extract on laying performance, egg quality, inflammatory responses,...

Experimental models have been extensively used to explore the effects of ginger extract (GE) on oxidative stress and immune response. However, the influence of GE dietary supplementation on gut microbial composition, function, and the resistome in laying hens remains not fully understood. This research investigated the impact of GE supplementation on laying performance, egg quality, metabolism, inflammation, and the gut microbiome and resistome in laying hens. Thirty healthy, 35-week-old Jingfen No.6 laying hens with consistent body weight and laying rate were randomly allocated to either the control group (Con; basal diet) or the ginger extract supplementation group (Con-G; basal diet with 5 g/kg GE), each with fifteen replicates (one hen per replicate). The pre-feeding period lasted one week, followed by an eight-week trial. The results revealed that average laying rate (P = 0.051) and egg mass (P < 0.05) significantly increased, while feed conversion efficiency improved (P < 0.05) in the GE-supplemented group during the study period. Additionally, egg quality, host metabolism, serum antioxidant levels, and histological assessments of the jejunum, ileum, and cecum tissues were positively affected by GE (P < 0.05). Notably, GE supplementation significantly decreased (P < 0.05) serum pro-inflammatory cytokines (IL-6, IL-1β, and TNF-α) and increased (P < 0.05) IgA, IgG, and IL-10 levels. LEfSe analysis revealed that the relative abundance of genera such as Ligilactobacillus salivarius, Limosilactobacillus vaginalis, Butyricimonas virosa, and Limosilactobacillus alvi were significantly increased (P < 0.05) in the Con-G group. Furthermore, ginger extract significantly enhanced (P < 0.05) the production of short-chain fatty acids(including acetate, propionate, butyrate, isovalerate, valerate, and lactate) in the cecum, modulated the expression profile of antibiotic resistance genes in the intestines of laying hens, and inhibited pathogen colonization. The study concludes that ginger extract supplementation in laying hen diets improves laying performance, egg quality, host metabolism, and immune responses, positively alters gut microbiota composition and functionality, and modulates the poultry resistome. Metagenomic analysis underscores the potential of GE as a safe and effective additive.