维生素C对凡纳滨对虾生长及抗病力的影响

以不同水平维生素C 2 磷酸酯 (添加量分别为 0、75、15 0、30 0和 6 0 0mg/kg)的饲料喂养凡纳滨对虾 10周 ,研究维生素C 2 磷酸酯对凡纳滨对虾生长及抗病力的影响。结果显示 :在养殖前 4周 ,饲料中添加维生素C 2 磷酸酯显著促进凡纳滨对虾的生长 ,然而对对虾的成活以及饲料利用不产生影响 (P >0 0 5 ) ;而到实验后期添加维生素C 2 磷酸酯不能促进凡纳滨对虾的生长 ,却显著提高凡纳滨对虾的成活率 (P <0 0 5 )。维生素C 2 磷酸酯对对虾体水分、脂肪、蛋白质和维生素C在肝胰脏中的积累量的影响显著 (P <0 0 5 ) ,对对虾体灰分影响不显著 (P >0 0 5 )。维生素C 2 磷酸酯对对虾血清中超氧化物歧化酶活力无显著影响 ,饲料中未添加维生素C或过量添加 (超过 30 0mg/kg饲料 )均导致血清中酚氧化酶活力、血细胞总数和溶菌酶活力的显著下降。以生长、成活和酚氧化酶活力为指标 ,饲料中维生素C 2 磷酸酯的适宜添加量为 15 0mg/kg。

EFFECT OF DIETARY VITAMIN C SUPPLEMENTATION ON GROWTH AND ANTI-DISEASE ABILITY OF SHRIMP,PENAEUS VANNAMEI

Agrowth trial was conducted to determine the effects of ascorbic acid-2-phosphate with dietary different supplementation levels(0,75,150,300 and 600mg/kg diet)on growth and anti-disease ability of shrimp( Penaeus vannamei )for 10 weeks.Five isonitrogenous and isoenergic diets were formulated as experimental diets.The results showed that in 4-weeks feeding trial,the diet with ascorbic acid-2-phosphate supplementation could significantly increase the growth rate of juvenile shrimp.While the survival rate was not affected( P >0 05).Up to 10-weeks feeding trial,there was no significant effect of increasing dietary ascorbic acid-2-phosphate on growth of shrimp.However the survival rate was improved significantly( P <0 05).The feed convention ratio and protein efficiency ratio were not affected by the dietary vitamin C supplementation levels.The whole body moisture,lipid,protein content and hepatopancreatic ascorbate concentrations were significantly affected by the dietary ascorbic acid-2-phosphate supplementation levels,while there was no significant effect of vitamin C on ash content in whole body.The ascorbic acid concentrations in the shrimp hepatopancreas increased significantly with the increase of the dietary vitamin C supplementation levels,the hepatopancreas ascorbic acid concentrations in the shrimp with vitamin C un-supplementation was the lowest.The superoxide dismutase(SOD)of shrimp serum was not affected by the dietary ascorbic acid-2-phosphate supplementation levels. The phenoloxidase activity, red blood count and lysozyme activity decreased significantly when the dietary without ascorbic acid-2-phosphate supplementation or excess of 150mg/kg supplementation.Based on weight gain rate,survival rate and phenoloxidase activity,the optimal dietary supplementation levels of ascorbic acid-2-phosphate for this diet formulation was 150mg/kg diet.