中文摘要：

以初始体质量（7.27±0.40） g的青鱼为研究对象, 采用维生素E（VE）有效含量分别为14.36（对照组）、25.14、37.66、62.97、113.92和210.45 mg/kg 6种等氮等能的实验饲料, 饲养青鱼幼鱼8周后, 根据生长情况选取对照组、62.97和210.45 mg/kg VE组进行24h氨氮胁迫（20 mg/L）, 研究VE对青鱼幼鱼生长、免疫及抗氨氮胁迫能力的影响。结果表明： 以特定生长率为指标, 折线模型分析表明青鱼有效维生素E需要量为45.00 mg/kg。肌肉、肝脏和血清VE含量与饲料中VE含量呈明显正相关, 当饲料VE含量超过113.92 mg/kg时, 肌肉和肝脏VE含量均达到饱和。VE对鳃丝Na＋/K＋-ATP酶活性（NKA）和血清皮质醇（COR）无显著影响, 但随着饲料VE含量的升高, 过氧化氢酶（CAT）和总超氧化物歧化酶活性（T-SOD）呈上升趋势, 丙二醛含量（MDA）呈下降趋势。氨氮胁迫对各处理组肌肉VE含量和血清CAT活性无影响, 但肝脏VE含量均显著降低（P〈0.05）, 且62.97和210.4 5 mg/kg VE组血清VE水平有所升高。在胁迫后, 对照组血清T-SOD、鳃丝NKA活性显著降低, 皮质醇含量显著增加（P〈0.05）。与对照组相比, 62.97和210.45 mg/kg VE组T-SOD、NKA活性和皮质醇含量在胁迫前后无显著变化。各处理组MDA含量在胁迫后虽均显著升高, 但210.45 mg/kg VE组在胁迫后MDA含量仍显著低于对照组（P〈0.05）。以上结果说明, 青鱼幼鱼获得最大生长的有效维生素E需求量为45.00 mg/kg, 且较高VE能有效提高青鱼机体免疫力, 缓解氨氮胁迫对青鱼机体的负面影响。

英文摘要：

An 8-week feeding experiment was conducted to evaluate the effects of dietary vitamin E （VE） supplementation on growth, immunity of juvenile black carp[initial average weight of （7.27±0.40） g] subjected to ammonia-nitrite stress. Six practical diets were formulated to contain 14.36 （control）, 25.14, 37.66, 62.97, 113.92, and 210.45 mg vitamin E equivalent/kg diet, supplied as VE acetate. After feeding for 8 weeks, according to growth, the black carp in control, 62.97 and 210.45 mg/kg vitamin E treatment groups were selected and subjected to ammonia-nitrite stress （20 mg/L） for 24h. The results indicated that the dietary VE content for the maximum specific growth rate （SGR） was about 45.0 mg/kg. The vitamin E levels in the tissues of liver, muscle and the serum were positively correlation with diet vitamin E content, and no significant differences were observed among fish fed with the diets that had equal to or higher than 113.92 mg/kg of vitamin E. No significant difference in gill Na＋/K＋-ATPase （NKA） activity were observed among these treatments. However, with increasing diet vitamin E content, activities of total superoxide dismutase （T-SOD） and catalase （CAT） increased, and malondialdehyde （MDA） content decreased. Each group of muscle vitamin E concentration and CAT activity were not affected by ammonia-nitrite stress, although liver vitamin E concentration decreased significantly and serum VE level increased in the 62.97and 210.45 mg/kg VE treatments. After the stress, T-SOD and gill NKA activities in the control group decreased significantly and cortisol content increased significantly （P〈0.05）. In comparison, activities of T-SOD, NKA and cortisol showed no significant changes. MDA content in each group increased significantly after stress. However, for the 210.45 mg/kg VE treatment group, MDA content was significantly lower than the control group （P〈0.05）. Our results indicated that the effective VE requirement of juvenile black carp for optimal growth ma