为考察低鱼粉饲料中添加晶体或微囊氨基酸对鲤生长性能的影响，配制了高鱼粉饲料［鱼粉含量前期(1～28 d)为15%，后期(29～56 d)为10%］和低鱼粉饲料［鱼粉含量前期为10%，后期为5%］，在低鱼粉饲料中分别添加晶体和微囊赖氨酸、蛋氨酸，并使赖氨酸、蛋氨酸水平与高鱼粉组一致，得晶体氨基酸饲料和微囊氨基酸饲料。选择体重为（5.0±0.5） g的健康鲤480尾，随机分为4组（每组3个重复，每个重复40尾），每组随机饲喂1种试验饲料。结果表明，与低鱼粉组相比，添加晶体氨基酸对鲤生长性能无显著改善（P>0.05），而添加微囊氨基酸则提高增重率8.67%（P<0.05），降低饲料系数7.46%（P<0.05）；在生长性能方面微囊氨基酸组与高鱼粉组没有显著差异（P>0.05）。鲤摄食上述4种饲料0、1、2、3、4、5 h后的血浆总游离氨基酸浓度测定结果表明，微囊氨基酸组的血浆总游离氨基酸含量的变化趋势与高鱼粉组、低鱼粉组一致，即在饲后3 h达到高峰，而添加晶体氨基酸使血浆总游离氨基酸含量的吸收峰值提前到饲后2 h。晶体赖氨酸与蛋氨酸经微囊化后，其溶失率显著降低（P<0.05），仅相当于晶体氨基酸的28.4%（赖氨酸）与4.9%（蛋氨酸）。上述结果表明，在低鱼粉实用饲料中补充晶体氨基酸对鲤的生长性能无显著改善作用，而补充微囊氨基酸则显著提高增重率，降低饲料系数。

The present experiment was conducted to explore the effects of supplementation of crystalline or micro-capsulated amino acids in low fish meal diet on growth performance of common carp (Cyprinus carpio）. Four diets were prepared, which were high fish meal （FM） diet with 15% FM in prophase (1 to 28 d) and 10% FM in anaphase (29 to 56 d), low FM diet with 10% FM in prophase and 5% FM in anaphase, low FM diet added with crystalline lysine and methionine, and low FM diet added with micro-capsulated lysine and methionine. The later two diets of each stage had the same lysine and methionine levels as the high FM diet. Common carp (5.0±0.5) g were fed the four diets with triplicate for 8 weeks. Four hundred and eighty healthy common carp with an initial body weight of (5.3±0.5) g were randomly assigned to 4 groups (with 3 replicates of 40 fish) and fish in each group were fed 1 experimental diet. The results were as follows: compared with the low FM group, supplementation of crystalline amino acids had no significant effect on growth performance (P>0.05), but the weight growth rate (WGR) was improved by 8.67% and feed conversion ratio (FCR) was decreased by 7.46% (P<0.05) by adding micro-capsulated amino acids in diet. The growth performance of micro-capsulated amino acid group was similar to that of the high FM group (P>0.05). Plasma total free amino acid (TFAA) content at 0, 1, 2, 3, 4, 5 h after feeding was determined, and the highest content of TFAA occurred at 3 h after feeding high FM diet, and low FM diet added without or with micro-capsulated amino acids, but absorbing peak occurred at 2 h after feeding low FM diet added with crystalline amino acids, which meant the absorbing peak was advanced. Dissolve-loss rates of crystalline lysine and methionine were significantly decreased by micro-capsulating, respectively (P<0.05), and the dissolve-loss rates of micro-capsulated lysine and methionine were equal to only 28.4% and 4.9% of the dissolve-loss rates of crystalline lysine and methionine, respectively. It is concluded that supplementation of micro-capsulated amino acids in low FM practical diet of common carp can improve WGR, and decrease FCR, but supplementation of crystalline amino acids in low FM practical diet of common carp can not affect the growth performance.［Chinese Journal of Animal Nutrition, 2010，22（6）:1599-1606］