中文摘要：

本试验旨在研究维生素E在罗非鱼幼鱼饲料中的应用及耐受性。选用400尾大小均匀 、健康的吉富罗非鱼幼鱼,随机分为5组,每组4个重复,每个重复20尾。各组分别投喂添加0（对照）、25、50、250、2 500 mg/kg维生素E的试验饲料。试验期56 d。结果表明：维生素E添加量为250 mg/kg组的鱼体增重率、特定生长率显著高于其他4组（P〈0.05）,其他4组间差异不显著（P〉0.05）;对照组成活率要低于其他4组,且差异与50和2 500 mg/kg组达到显著水平（P〈0.05）。维生素E添加量为250 mg/kg组的血清超氧化物歧化酶、过氧化氢酶活性显著高于对照组（P〈0.05）,肝胰脏超氧化物歧化酶活性显著高于对照组（P〈0.05）。维生素E添加量为250 mg/kg组的血清和肝胰脏丙二醛含量显著高于对照组（P〈0.05）。结果提示,维生素E能提高罗非鱼幼鱼生长性能,增强机体抗氧化能力。过量的维生素E虽能降低罗非鱼的脂质过氧化反应,但同时会抑制罗非鱼幼鱼生长。根据罗非鱼幼鱼生长性能、抗氧化酶活性及生化指标,确定维生素E对罗非鱼幼鱼56 d最大未观察到有害作用剂量为8.50 mg/（kg·d）。

英文摘要：

This study was conducted to investigate the application and tolerance of vitamin E in diets of juvenile tilapia. A total of 400 healthy juvenile tilapia （GIFT, Oreochromis niloticus） with an average body weight of （3.25±0.02） g were randomly assigned to 5 groups with 4 replicates per group and 20 fish per replicate. The fish in the five groups were fed the experimental diets supplemented with 0 （control）, 25, 50, 250 and 2 500 mg/kg vitamin E, respectively. The experiment lasted for 56 d. The results showed that weight gain rate and special growth rate of fish in 250 mg/kg group were significantly higher than those in other four groups （P〈0.05）, but there were no significant difference among these four groups （P〉0.05）; the survival rate in control group was lower than that in other four groups and was significantly lower than that in 50 and 2 500 mg/kg groups （P〈0.05）. The activities of superoxide dismutase （SOD） and catalase in serum in 250 mg/kg group were significantly higher than those in control group （P〈0.05）, and the hepatopancreas SOD activity in 250 mg/kg group was significantly higher than that in control group （P〈0.05）. The content of malondialdehyde in serum and hepatopancreas in 250 mg/kg group was significantly higher than that in control group （P〈0.05）. The results indicate that vitamin E can promote growth performance and antioxidant ability of juvenile tilapia. Although ultrahigh level of vitamin E can decrease the lipid peroxidation, growth of tilapia juvenile is restrained. According to the growth performance, antioxidase activity and biochemical index, the 56 d no observed adverse effect level for vitamin E in juvenile tilapia is 8.50 mg/（kg·d）.