饲料牛磺酸含量对不同生长阶段尼罗罗非鱼生长性能的影响

Effect of dietary taurine level on growth performance of Nile tilapia(Oreochromis niloticus)at different growth steges

试验旨在研究不同生长阶段下饲料牛磺酸含量对尼罗罗非鱼生长性能的影响。试验以酪蛋白和明胶(不含牛磺酸)作为蛋白源,配制成4种不同牛磺酸含量(0、400、800、1 200 mg/kg)的试验料,分别用来饲喂尼罗罗非鱼(Oreochromis niloticus),饲喂期为84 d。整个饲喂期分三个生长阶段:第1个生长阶段(1～28 d)、第2个生长阶段(29～56 d)和第3个生长阶段(57～84 d)。结果表明,在每个生长阶段,以800 mg/kg牛磺酸饲料组试验鱼的增重率为最大且明显高于其他各组(P<0.05),以对照组的增重率为最低且明显低于其他各组(P<0.05),但饲料效率不受牛磺酸含量的影响。各牛磺酸添加组的摄食率明显高于对照组(P<0.05),但牛磺酸添加组之间差异不明显。在饲喂的第84 d,牛磺酸添加组尼罗罗非鱼体成分中粗蛋白质和粗脂肪含量均明显高于对照组(P<0.05)。以增重率为指标,用二次曲线回归拟合的方程得出三个生长阶段下尼罗罗非鱼幼鱼对牛磺酸的需要量分别为0.72%、0.68%和0.64%。该试验结果显示尼罗罗非鱼幼鱼对牛磺酸的需要量是随着年龄增加而下降的。

The experimental was conducted to investigate the effect of dietary taurine content on growth performance of Nile tilapia at different growth steges. The four experimental diets were tormulat- ed to contain four levels of taurine （0, 400, 800, 1 200 mg/kg） using casein and gelatin （taurine free） as protein sources. Four groups of Nile tilapia juveniles （Oreoehromis niloticus） were hand-fed the four diets across a feed period of 84 d. The whole feed period was divided into three growth stages： the first growth stage （1-28 d）, the second growth stage （29~56 d） and the third growth stage （57~84 d）. At each growth stage, the weight gain rate in 800 mg/kg taurine group was highest among groups, and significantly higher than that of the other groups（P〈0.05）, while the lowest weight gain rate was found in the control group, and was markedly lower than that of other groups（P〈0.05）： There is no difference in feed efficiency among groups; The feeding rate in taurine-added groups is signifi- cantly higher than in the control （P〈0.05）. The crude protein and erude fat content of whole- body fish in taurine-added groups were signifi- eantly higher than that in the control group （P〈0.05）. On the basis of the quadratic curve regression analysis, the requirements of taurine fi）r juvenile Nile tilapia at different growth stages were 0.72%, 0.68% and 0.64%, respectively. The results showed that Nile tilapia would gradually reduce taurine requirement with age.