Taurine is a β sulphonic amino acid and is conditionally essential for many fish species. In the present study, the effect of dietary taurine (tau) on Pangasianodon hypophthalmus fry (initial mean weight 0.8 ± 0.6 g) was evaluated by feeding six isonitrogenous (370 g/kg crude protein) and isolipidic (100 g/kg crude lipid) casein-based purified diets with graded levels of tau at 0 (basal diet), 5, 10, 15, 20, and 25 g/kg feed. Fish were randomly stocked in triplicate groups in 100 L plastic tubs and fed to apparent satiation over two feedings at 10.00 and 16.00 hr daily for 45 days. Final weight, weight gain, specific growth rate, and protein efficiency ratio improved significantly (p < .05) with increasing dietary tau up to 15 g/kg feed and plateaued thereafter. Whole-body protein content did not change beyond tau 15 g/kg feed, but carcass lipid content significantly (p < .05) decreased. The group of fish fed with tau 25 g/kg feed exhibited significantly higher (p < .05) superoxide dismutase, catalase, and glutathione s-transferase activity. According to the findings of this study, the optimum dietary tau content in P. hypophthalmus fry feed was estimated to be 15.05–16.31 g/kg feed as per the broken-line regression analysis based on weight gain and nutrient utilization against dietary taurine.

中文翻译：

---

日粮牛磺酸改善了 pangasius Pangasianodon hypophthalmus 的生长性能、养分利用和抗氧化酶活性

牛磺酸是一种 β 磺酸氨基酸，对许多鱼类来说是有条件必需的。在本研究中，饲料牛磺酸 (tau) 对Pangasianodon hypophthalmus鱼苗（初始平均体重 0.8 ± 0.6 g）的影响通过饲喂六种异氮（370 g/kg 粗蛋白）和异脂（100 g/kg 粗脂）来评估以酪蛋白为基础的纯化日粮，tau 水平分级为 0（基础日粮）、5、10、15、20 和 25 g/kg 饲料。鱼在 100 L 塑料桶中随机放养，一式三份，每天 10.00 和 16.00 小时两次喂食至明显饱食，持续 45 天。终重、增重、比生长率和蛋白质效率比显着提高（p < .05) 随着日粮 tau 增加至 15 g/kg 饲料，此后趋于平稳。全身蛋白质含量在 tau 15 g/kg 饲料后没有变化，但胴体脂质含量显着下降 ( p  < .05)。喂食 tau 25 g/kg 饲料的鱼组表现出显着更高的 ( p  < .05) 超氧化物歧化酶、过氧化氢酶和谷胱甘肽 s-转移酶活性。根据本研究的结果，根据基于增重和养分利用对日粮牛磺酸的折线回归分析，估计P. hypophthalmus鱼苗饲料中的最佳日粮 tau 含量为 15.05-16.31 g/kg 饲料。