中文摘要：

将初始体质量（0.42±0.05）g的杂交鲟（Acipenser schrenckii♀×A.baerii♂）仔鱼饲养在室内循环水养殖系统中,投喂添加0（G1）、0.25%（G2）、0.5%（G3）、0.75%（G4）和1.0%（G5）L-丙氨酰-L-谷氨酰胺（L-AG）的5种等氮饲料,每个处理3个重复,每个重复1500尾鱼,研究L-AG水平对杂交鲟体成分和十二指肠形态的影响。56d的养殖结果表明：饲料中添加0.25%和5.0%L-AG对全鱼粗蛋白含量影响不显著（P〉0.05）,但添加0.75%和1.0%L-AG显著提高了全鱼粗蛋白含量（P〈0.05）。添加0.25%~1.0%L-AG对全鱼水分、粗脂肪和灰分含量影响不显著（P〉0.05）。与对照组相比,添加0.25%~1.0%L-AG对肠道绒毛高度、微绒毛高度和肌层厚度均未产生显著影响（P〉0.05）。结果表明：外源补充0.75%~1.0%L-AG可显著提高杂交鲟仔鱼粗蛋白含量,但添加0.25%~1.0%L-AG对十二指肠形态不产生显著影响。

英文摘要：

Juvenile hybrid sturgeon （A cipenser schrenckii ♀ ×A. baerii♂ ） with initial body weight of （0.42＋ 0.05） g were reared in a recirculation system and fed five isonitrogenous and isocaloric diets supplemented with L-Alanyl-L- Glutamine （L-AG） at a dose of 0% （G1）, 0.25% （G2）, 0.5% （G3）, 0.75% （G4） or 1.0% for 56 days with triplication to evaluate the effects of （L-AG） on body composition and duodenal morphology of the fish. The results showed that there were no significant differences in body crude protein content in the fish fed the diets containing 0.25% and 5.0% ofL-AG （P〉0.05）. However, the fish fed the diets containing 0.75% and 1.0% of L-AG had increased in body crude protein content （P〈0.05）, without significant differences in body moisture, crude lipid and ash among the groups （P〉0.05）. No significant differences in intestinal villus height, microvillus height and muscle thickness were ob- served in the fish among the groups （P〉0.05）. In conclusion, body crude protein was significantly affected by 0.75% - 1.0% L-AG supplementation, however, duodenal morphology was not changed by 0.25% - 1.0% L-AG supplementation.