饲料Vc对异育银鲫的生理效应及其适宜添加量

Physiological effects of dietary vitamin C on allogygenetic silver crucian carp (Carassius auratus gibelio Bloch ♀×Cyprinus carpio var. singuonensis ♂)and the optimal supplementation

在精制饲料中分别添加不同剂量Vc(0、37.5、75、15 0、30 0、6 0 0和 12 0 0mg/kg) ,连续投喂异育银鲫 (方正银鲫♀×兴国红鲤♂ ) (Carassiusauratusgitelio) 8周。结果显示 ,当饲料中缺乏Vc时异育银鲫虽没有出现明显的缺乏症状 ,但日增重率、血红蛋白含量和血清POD酶活性均低于Vc添加组 ,而红细胞脆性极显著地高于高剂量Vc添加组 (P <0 .0 1) ;同时 ,经新复极差检验 ,在适宜范围内随着饲料Vc含量增加 ,异育银鲫日增重率、血红蛋白含量、POD活性等指标显著提高 ,而红细胞脆性明显下降 (P <0 .0 5 )。综合以上指标的非线性回归分析结果 ,建议生产上异育银鲫饲料Vc适宜添加量为 30 0～ 5 0 0mg/kg。

The refined diets were added with Vc at a gradient of 0, 37.5, 75, 150, 300, 600 and 1 200 mg/kg diet. The allogygenetic silver crucian carp, body weight 41-43 g, were cultured in a recirculation filtered water system and fed for 8 weeks at water temperature (25±1)℃. The analyzed data show that the fish fed no Vc diets do not show any symptom of Vc deficiency, but the daily weight increment rate, hemoglobin level and serum peroxidase activity are all lower than those of the Vc diet groups(P<0.01), while the osmotic hemocytolysis is higher than that of the Vc diets groups. With the increase of Vc in diets within 37.5 to 600 mg/kg, the fish grow better and better with the decrease of osmotic hemocytolysis and increase of hemoglobin content and POD activity significantly (P<0.05) as evidenced from Duncan's LSR test. From the comprehensive results by nonlinear regression analysis, the conclusion is that the maximum Vc level in diets are 300-500 mg/kg for allogygenetic silver crucian carp.