中文摘要：

以初始体重（5．90±0．01）g的青鱼（Mylopharyngodon piceus）为研究对象，用豆粕替代不同水平鱼粉，配制5种等氮等能的实验饲料，分别为30％鱼粉（对照组）、25％鱼粉、20％鱼粉、15％鱼粉和15％鱼粉＋晶体氨基酸，试验持续8周。结果显示：当鱼粉含量为15％时，其增重率、特定生长率、肌肉鲜味氨基酸含量和总氨基酸含量显著低于对照组，而饲料系数则显著高于对照组，添加晶体氨基酸对青鱼生长无显著改善；各处理组间甘油三酯（TG）、总蛋白（TP）、总胆固醇（TC）含量及谷丙转氨酶（ALT）活性无显著差异，但15％鱼粉组和15％鱼粉＋晶体氨基酸组的青鱼的血糖含量和谷丙转氨酶活性显著高于对照组。结果表明，青鱼幼鱼实用饲料中鱼粉含量以不低于20％为宜，添加晶体氨基酸对青鱼幼鱼的生长无改善作用。

英文摘要：

An 8-week feeding experiment was conducted to evaluate the effect of dietary soybean meal （ SBM ） levels on growth and some blood physiological-biochemical indices in juvenile black carp [ initial average weight of （5.90 ± 0. 01 ） g- I A typical diet with 30% fish meal （FM） was used as the control. The other experimental diets in which fish meal was replaced by different levels of soybean meal were formulated with 25% FM, 20% FM, 15% FM and 15% FM added with crystalline amino acids （CAA） respectively on an isocaloric basis. The results showed that the weight gain rate and specific growth rate of juvenile black carp were significantly lower than those fed control diet when fish fed the diet with FM level up to 15% , and growth performance of juvenile black carp could not be improved by adding CAA. The delicious amino acid （DAA） and total amino acid （TAA） contents of muscle were significantly reduced in fish fed diet with FM level up to 15% than those fed control diet. No significant dilterences in serum triglyeeride （TG）, total cholesterol （TC） , total pro- tein （TP） contents and ALT activity were observed among dieta13~ treatments, but GLU content and AST activity in serum were significantly higher in 15% FM diet and 15% FM ＋ CAA diet than those fed control diet. Based on these observations above, the fish meal content for juvenile black carp should not be less than the level of 20% , and supplementations of CAA in low fish meal diet could not improve the growth performance of juvenile black carp.