无鱼粉饲料中添加Ala-Gln对施氏鲟幼鱼生长和能量代谢的影响OA

This study was conducted to investigate the effects of different gradients of Ala-Gln added to fishmeal-free diets on the growth performance,amino acid metabolism and energy budget of juvenile Acipenser schrenckii.In this study,450 juvenile sturgeon with initial body weight of(21.66±1.02)g were raised in a recirculating water culture facility and randomly divided into 5 groups(3 replicates per group with 30 fish per replicate).The control group was fed a basal diet,while the experimental groups were fed diets supplemented with 0,0.25％,0.50％,0.75％,and 1.00％Ala-Gln,respectively.The experiment lasted for 56 days.The results were as follows:(1)The final weight and condition factor of sturgeon were significantly higher in the groups receiving 0.50％-1.00％Ala-Gln compared to the control group(P＜0.05).Weight gain rate,feed efficiency,dry matter intake,crude protein,and crude lipid content increased with Ala-Gln supplementation,though these increases did not reach statistical significance(P＞0.05).(2)Fecal energy(F),excretion energy(U),showed no significant differences(P＞0.05),but growth energy(G)and metabolizable energy(R)were significantly different from the control group(P＜0.05).(3)The cysteine content of fish supplemented with 0.75％Ala-Gln was significantly higher than that of other groups(P＜0.05).The glycine content of fish supplemented with 0.50％Ala-Gln was significantly higher than that of other groups(P＜0.05).The glycine content of fish supplemented with 0.50％Ala-Gln was significantly higher than that of other groups(P＜0.05).(4)Glutamine and alanine levels in the blood were significantly increased 5 hours after ingestion(P＜0.05).After 0.25％-1.00％Ala-Gln supplementation,glutamine was the most important amino acid affecting the blood metabolic profile.The addition of 0.50％Ala-Gln resulted in significantly higher aspartic acid levels compared to other groups(P＜0.05).Analysis of PLA,a key component of aspartic acid,indicated that glutamine was the most important amino acid influencing the blood metabolic profile.The results indicate that exogenous supplementation of 0.75％to 1.00％Ala-Gln can significantly improve the growth performance of juvenile sturgeon,likely due to increased absorption of Ala-Gln,which elevates the levels of glutamine and alanine in the body,thereby affecting metabolism and promoting protein synthesis.