Maternal β-carotene supplementation improves offspring growth, development, immunity, and intestinal microbiota in chickens via immune-mediated and microbial-mediated maternal effects.

In poultry, maternal nutritional interventions affect the development and intestinal microbiota of embryos. β-carotene possesses immune-boosting and gut microbiota-regulating properties. We examined the influences of supplementing hen diets with β-carotene on offspring growth, development, and immunity to determine whether maternal β-carotene benefits offspring health. Our findings showed that β-carotene increased serum IgG, lysozyme, and beta-defensins in hens, subsequently elevated these parameters in the serum of their offspring, and promoted their growth and development. In offspring, there were significant positive correlations between body weights and intestinal development indices with serum lysozyme and beta-defensin levels. The augmentation of vertical transfer of lysozyme and beta-defensins may be linked to the increased expression of these genes in the maternal jejunum. The number of shared taxa between the magnum and offspring gut is higher than that between the maternal gut and offspring. Among the taxa, were increased in the maternal magnum and gut microbiome, only the Caloramator abundance was significantly elevated in the guts of 21-day-old offspring. In conclusion, maternal β-carotene inclusion improves offspring growth and development, potentially through enhancing maternal intestinal immunity and thereby promoting immune-mediated maternal effects. The vertical transfer of maternal microbes to offspring exhibits selectivity in chicken.