L-丙氨酰-L-谷氨酰胺对低氧胁迫后军曹鱼幼鱼生长性能、血清生化与抗氧化指标的影响

Effects of L-Akanyl-L-Glutamine on Growth Performance,Serum Biochemical and Antioxidant Indexes of Juvenile Cobia(Rachycentron canadum)after Hypoxia Stress

本试验旨在为探究L-丙氨酰-L-谷氨酰胺(Ala-Gln)对低氧胁迫后军曹鱼幼鱼生长性能、血清生化与抗氧化指标的影响。以低氧胁迫14 d后的军曹鱼幼鱼[(105.16±6.01)g]为研究对象,随机分为4组,每组3个重复,每个重复30尾。4组试验鱼分别投喂Ala-Gln添加量为0(对照组)、0.5%、1.0%、1.5%配制4种等氮等脂的试验饲料,并分别于试验第7、14、28天采集血清进行指标测定。结果显示:1)与对照组相比,在饲喂14与28 d时,1.0%组和1.5%组的增重率和特定生长率显著升高(P<0.05),饲料系数显著降低(P<0.05)。2)与对照组相比,在饲喂28 d时,1.0%组和1.5%组血清中甘油三酯和总胆固醇含量显著降低(P<0.05),所有添加Ala-Gln组血清中葡萄糖、总蛋白和白蛋白含量显著升高(P<0.05),1.5%组血清中谷草转氨酶与谷丙转氨酶活性显著升高(P<0.05)。3)与对照组相比,在饲喂28 d时,1.0%组和1.5%组血清中超氧化物歧化酶、过氧化氢酶和谷胱甘肽过氧化物酶活性显著升高(P<0.05),血清丙二醛含量显著降低(P<0.05)。以上结果表明,饲料中添加1.0%Ala-Gln可提高军曹鱼幼鱼血清中TP和ALB的含量以及减少血清中TC和TG的堆积,提高生长性能与抗氧化能力,改善低氧胁迫所带来的氧化损伤。

This experiment aimed to investigate the effects of L-akanyl-L-glutamine(Ala-Gln)on growth performance,serum biochemical and antioxidant indexes of juvenile cobia after hypoxia stress.After 14 days of hypoxia stress with an average body weight of(105.16±6.01)g,the juvenile cobias were selected and divided into 3 groups with 3 replicates per group and 30 fish per replicate and they were fed five isonitrogenous and isolipidic diets which contained 0(control group),0.50%,1.00%and 1.50%Ala-Gln,respectively.The serum samples were sampled randomly for index analysis on days 7,14 and 28 of trial.The results showed as follows:1)in 1.0%and 1.5% groups,the weight gain rate(WGR)and specific growth rate(SGR)were significantly higher than those in the control group(P<0.05),while the feed conversion ratio(FCR)was significantly lower than that in the control group at 14 and 28 d of feeding(P<0.05).2)Compared with the control group,the serum triglyceride(TG)and total cholesterol(TC)contents in the 1.0% and 1.5% groups decreased significantly(P<0.05),the serum glucose(GLU),total protein(TP)and albumin(ALB)contents increased significantly in the all Ala-Gln supplementation groups(P<0.05),and the serum aspartate aminotransferase(AST)and alanine transaminase(ALT)activities in the 1.5% group increased significantly at 28 d of feeding(P<0.05).3)In 1.0%and 1.5% groups,the serum superoxide dismutase(SOD),catalase(CAT)and glutathione peroxidase(GPx)activities were significantly higher than those in the control group(P<0.05),and serum malondialdehyde(MDA)content was significantly lower than that in the control group at 28 d of feeding(P<0.05).The aforementioned findings demonstrate that adding 1.0%Ala-Gln to the diet can enhance the contents of TP and ALB in serum,decrease the buildup of TC and TG in the serum,enhance the growth performance and antioxidant capacity,and lessen the oxidative damage of juvenile cobia caused by hypoxia stress.