饲料中Vc水平对中华鳖幼鳖生长及其组织中含量的影响

EFFECT OF DIETARY Vc SUPPLEMENTATION ON GROWTH AND TISSUE Vc CONTENT IN JUVENILE SOFT-SHELL TURTLE TRIONYX SINENSIS

以中华鳖幼鳖为研究对象 ,以高稳定性维生素C磷酸酯为Vc源 ,研究饲料添加Vc对中华鳖生长及其Vc在组织中含量的影响。试验分别投喂基础配方相同而分别添加Vc 0、5 0、10 0、2 0 0、4 0 0、80 0mg/kg的饲料 ,在水温 31±2℃条件下养殖于结构相同、面积分别为 10 .5m2 的 18口水泥池中 ,进行为期 10 5d的养殖试验。结果表明 :(1)饲料添加Vc可提高中华鳖幼鳖增重率 ,其中添加 2 0 0mg/kg组效果最佳 ,与未添加组间差异显著 (P <0 .0 5 ) ;饲料添加Vc能提高蛋白质转化效率 ,添加Vc2 0 0、4 0 0、80 0mg/kg组与不添加的对照组之间差异均显著 (P <0 .0 5 ) ;而且 ,饲料添加Vc能降低饵料系数 ,但未达到显著差异 (P >0 .0 5 ) ;未添加的对照组和低剂量组未见有Vc缺乏症产生。(2 )基于试验幼鳖增重率折线法分析 ,中华鳖幼鳖获得最佳生长时的饲料Vc最低需求量为 184mg/kg ;(3)肝脏中Vc含量随着饲料Vc添加水平上升而增加 ,相关系数达 0 .95 4 2 ,各添加组与未添加组间有显著差异 (P <0 .0 5 ) ;肝脏Vc含量的回归分析表明 ,获得维持肝脏组织Vc储存最佳的饲料Vc添加水平为 192mg/kg。 (4)饲料添加Vc可显著地降低鳖体水分含量 (P <0 .0 1) ,并略能增加体脂沉积 (P >0 .0 5 )。

A 105 day growth trial was conducted to investigate the effect of dietary vitamin C supplementation on growth,body composition,tissue Vc concentration in juvenile soft shell turtle Trionyx sinensis . White fish meal basal diet was formulated and Vc were added at the levels of 0,50,100,200,400,800mg L ascorbic acid per kg diets on ascorbic acid equivalent basis in the form of phosphorylated L ascorbic acid. The experiment was conducted in triplicates at 31±2℃ and the turtles were cultured in 18 same construction concrete tanks with area 10.5m 2 per each.The results showed that: 1) The supplementary dietary Vc could improve percentage of body weight increase,and there is a significant difference between the treatment with adding Vc 200mg/kg and the control( P <0.05);improve protein efficiency ratio,and there is a significant difference between the treatments with adding Vc 200,400,800mg/kg and the control( P <0.05); and reduce feed conversion ratio,but there is no significant difference between the treatments and the control( P >0.05).In addition,there was no any deficiency symptom observed in experimental turtles fed diet without or with low dietary Vc supplementation. 2) Based on broken line analysis,the minimum dietary Vc supplementation for maximum growth of juvenile soft shell turtle is 184mg/kg. 3) The Vc concentration in liver linearly increased with dietary Vc supplementation (R 2=0.9542). There is a significant difference on Vc concentration in liver between the control and the treatments( P <0.05). In order to get the optimum Vc concentration in liver, the Vc added in diet is 192mg/kg based on the regression analysis of liver Vc concentrations. 4) The dietary Vc supplementation could significantly reduce water content( P <0.01) and slightly increase fat content( P >0.05)in turtle whole body composition.