饲料牛磺酸对尼罗罗非鱼生长、体成分及组织游离氨基酸含量的影响

本文探讨了饲料牛磺酸水平对尼罗罗非鱼幼鱼生长性能、体成分及游离氨基酸含量的影响。选用体重为5.89±0.03g的罗非鱼300尾,随机分为5个处理组,每个处理3个重复,每个重复20尾。在基础饲料中分别添加0、0.4%、0.8%、1.2%、1.6%的牛磺酸,配制成5种试验料,分别饲喂不同处理组的罗非鱼,饲养周期为56d。结果表明： 0.8%牛磺酸组罗非鱼增重率最高,且显著高于0%和1.6%组(P<0.05)；饲料牛磺酸水平(0.4%-1.2%)显著提高了罗非鱼摄食率、肝脏指数和内脏指数,显著降低了饲料系数(P<0.05)。随着饲料牛磺酸水平的提高,鱼体粗蛋白质和粗脂肪含量随之升高,鱼体水分和粗灰分含量随之降低(P<0.05)；以增重率为指标,通过二次曲线回归分析得出罗非鱼饲料牛磺酸最适需要量为0.75%。罗非鱼血清、肝脏、肌肉和全鱼中牛磺酸含量与饲料牛磺酸含量存在正相关关系,且牛磺酸添加组血清、肝脏、肌肉和全鱼牛磺酸含量显著高于对照组相(P<0.05)。罗非鱼肝脏和肌肉中游离氨基酸含量随饲料牛磺酸含量的增加均呈逐渐下降的趋势,且牛磺酸添加组肝脏和肌肉中游离氨基酸含量显著低于对照组(P<0.05)。

Effects of taurine supplementation on the growth,body composition and tissue free amino acid concentrations in Nile tilapia(Oreochromis niloticus)

The nutritional effects of dietary taurine on growth, body composition and tissue free amino acid concentrations in Nile tilapia were evaluated. Three hundred tilapias (at 5.89 g of initial body weight) were randomly divided into five groups with three replicate tanks at a stock density of twenty fish in each replicate. Five diets were formulated to contain 0, 0.4%, 0.8%, 1.2%, and 1.6% taurine and were allocated to one of the groups of fish twice a day in a feeding period of 56 days. The fish fed the diet at 0.8% taurine got highest percent weight gain (P<0.05); Dietary taurine level at 0.4%-1.2% increased feed intake, hepatosomatic index and viscera index, but reduced feed conversion ratio (P<0.05); Both body moisture and ash contents decreased but both body protein and lipid contents incerased with the increase in dietary taurine (P<0.05); Quadratic cruve analysis based on weight gain indicated that the optimal level of dietary taurine for tilapia growth was 0.75%. Taurine concentrations in serum, liver, muscle and whole-body-fish were positively linearly correlated with the dietary taurine levels, and the values for these tissues in taurine-treated groups were significantly higher than that of control group (P<0.05). With the increase in dietary taurine, free amino acid concentrations in liver and muscle gradually decreased, and the values in taurine-treated groups were significantly lower than that in control group (P<0.05).