Taurine Supplementation in Low-Fishmeal of Golden Pompano (Trachinotus ovatus) Diets: Improving Intestinal Health and Alleviation of Inflammatory Response.

This research explored the effects of supplementing taurine in a low-fishmeal diet on the growth, hepatic antioxidant capacity, muscle quality, intestinal health, and alleviation of inflammatory response of golden pompano (Trachinotus ovatus). Over an eight-week period, 300 juvenile fish (initial weight 9.4 ± 0.47 g) were randomly allocated into 12 net enclosures (1.0 × 1.0 × 1.5 m), with each treatment group comprising three replicate cages containing 25 specimens. The results demonstrated that an optimal taurine inclusion level of 1.0-1.5% significantly promoted growth, as evidenced by the increased weight gain rate (WGR) and specific growth rate (SGR). It also protected hepatic health by reducing alanine aminotransferase (ALT) activity and enhancing antioxidant capacity. Activation of the hepatic Nrf2/Keap-1/HO-1 signaling pathway increased the level of antioxidant gene expression, including catalase (CAT) and superoxide dismutase (SOD). In addition, the appropriate supplementation of taurine significantly down-regulated muscle hardness-related genes (cathepsin B (CatB) and cathepsin L (CatL)) and promoted the growth and differentiation of myoblasts, thus improving muscle quality. The chymotrypsin of fish fed the A25T10 diet was significantly higher than those in other groups (p < 0.05). The amylase (AMY) of fish fed the A25T15 diet was significantly higher than those in other groups (p < 0.05). The Chao1, Shannon, and Simpson of fish fed the A25T15 diet were significantly higher than those in other groups (p < 0.05). Proteobacteria were the most abundant in group A25T10. The relative abundance of Photobacterium rose in the A25RT10 group. In this study, taurine supplementation can down-regulate the expression of intestinal pro-inflammatory factors (interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), interleukin-8 (IL-8)) and up-regulate the expression of anti-inflammatory factor interleukin-10 (IL-10), enhance intestinal immunity, and improve intestinal digestion and absorption. Therefore, the addition of 1-1.5% taurine to low-fishmeal feeds can improve the growth performance of golden pompano.