Dietary taurine-mediated alleviation of post-hatch transport stress in broilers: Improvements in growth, antioxidant status, and intestinal barrier integrity linked to gut microbiota modulation

This study investigated the effects of dietary taurine (Tau) supplementation on growth performance, antioxidant capacity, intestinal barrier function, and gut microbiota in yellow-feathered broilers exposed to post-hatch transport stress (TS). A total of 180 1-d-old chicks (initial body weight 35.93 ± 0.26 g) were randomly divided into five treatments, with six replicates each group and six birds each replicate, including control, TS, TS + 0.25% Tau, TS + 0.50% Tau, and TS + 0.75% Tau. The experiment lasted for two weeks. Compared with the control, post-hatch TS reduced final body weight (BW), average daily gain (ADG), plasma catalase (CAT) activity, and villus height (VH) in duodenum and ileum at d 7, while increasing plasma aspartate aminotransferase (AST) activity, cortisol level at d 7 and jejunal relative mRNA expression levels of HSP40 , HSP70 , and HSP90 ( P < 0.05). Compared with the TS group, dietary Tau supplementation significantly increased final BW, ADG, plasma glucose level at d 14, CAT activity, duodenal VH at d 7, but decreased plasma AST activity and duodenal crypt depth at d 14 ( P < 0.05). Meanwhile, compared with the TS group, the relative mRNA expression levels of TJP1 , TJP2 , LC3Ⅰ , LC3Ⅱ , and PRKN in the jejunum were upregulated, and the jejunal relative mRNA expression levels of HSP40 were downregulated by TS + 0.50% Tau ( P < 0.05). Compared with the TS group, the gut microbiome analysis revealed that TS + 0.50% Tau significantly improved the cecal microbial Shannon and Simpson indexes ( P < 0.05). Compared with TS group, dietary Tau supplementation increased the relative abundance of Firmicutes at d 7, Defluviitaleaceae_UCG-011 , Shuttleworthia , and Subdoligranulum at at d 14, and decreased the relative abundance of Proteobacteria at d 7 and 14 ( P < 0.05). Spearman correlation analysis revealed that the ADG during d 1-14 and plasma CAT activity positively correlated with the relative abundance of Shuttleworthia and Defluviitaleaceae_UCG-011 , while plasma CAT activity and LC3Ⅰ and LC3Ⅱ relative mRNA expression negatively correlated with the relative abundance of Proteobacteria and Escherichia-Shigella ( P < 0.05). Collectively, dietary Tau supplementation improved growth performance, antioxidant capacity, and intestinal barrier integrity in yellow-feathered broilers subjected to post-hatch TS, which might be linked to the alterations of gut microbiota.