牛磺酸对幼刺参生长、抗氧化和代谢酶活性的影响OACHSSCDCSTPCD

[Objective]To investigate the taurine synthesis ability of junvenile sea cucumber(Apostichopus japonicus)and its requirement for dietary taurine by analyzing the effects of dietary taurine on growth,body composition,antioxidation and digestion.[Method]Sea cucumber with initial weight of(11.40±0.04)g was used in the experimentexperiment.0(control),0.30%,0.60%,0.90%,1.20%,and 1.50%coated taurine as well as 0.60%cysteine and 0.60%sulfoalanine were added to the basic feed to form 8 isonitrogenous and isolipdic diets.The experiment was conducted in a tank(400 L),and each diet was put into three replicate tanks(30 per tank)once a day.The experiment lasted 56 days.The indicators of growth performance,antioxidant and metabolic enzyme activity of sea cucumber were measured.[Result]At the end of experiment,diets with 0.30%-1.50%taurine significantly increased the final weight,weight gain,and specific growth rate,while diets with 0.60%-1.50%taurine significantly increased the feces production rate(P<0.05).The ash content of whole body in groups of 1.20%and 1.50%taurine and the protein content of whole body in groups of 0.60%,0.90%and 1.20%taurine were significantly higher than those in the control group(P<0.05).As taurine level increased,the contents of threonine,valine,methionine,phenylalanine,glycine,cysteine,and proline increased while histidine and aspartic acid contents decreased.Leucine content first increased and then decreased,and the mean content in group of 0.90%taurine is the highest with significant difference(P<0.05)from the control group.The taurine content in respiratory tree and intestine gradually increased and then plateaued.Diets with 0.60%-1.50%taurine significantly increased taurine content of body wall,and all taurine treatments significantly increased intestine taurine content(P<0.05).The intestinal taurine content was significantly higher in sulfonylalanine group than that of the control group,but lower than those fed 1.20%-1.50%taurine(P<0.05).The activities of intestinal lipase,amylase,and pyruvate kinase first increased and then decreased with dietary taurine increasing,and the maximum values were observed in 0.9%taurine group.All taurine-supplemented diets increased the activities of intestinal glucokinase and alkaline phosphatase(P<0.05).The activities of cysteine sulfite decarboxylase and cysteine dioxygenase gradually decreased with dietary taurine increasing.The activities of intestinal catalase and superoxide dismutase first increased and then decreased with the increase of dietary taurine,reaching the maximum values in 0.90%and 1.20%taurine groups,respectively,while intestinal malondialdehyde content followed an opposite trend,and was significantly lower in groups of 0.90%,1.20%,1.5%taurine than that in the control group.[Conclusion]Broken line analysis using specific growth rate,fecal production rate,respiratory tree,and intestinal taurine accumulation level as evaluation indicators,combined with indicators such as digestive enzymes and antioxidant capacity,showed that the optimal levelof taurine in feed for junvenile sea cucumber with an initial mass of(11.40±0.04)g was 0.47%-0.51%.