维生素C对大口黑鲈生长与非特异性免疫的影响

用添加不同剂量维生素C(分别为0、0.5、1、2、4 g/kg)的饲料喂养初始体重为19 g左右的大口黑鲈Micropterus salmoides 2个月,研究维生素C对大口黑鲈生长及非特异性免疫的影响.结果显示:饲料中添加维生素C＞1 g/kg,能显著促进大口黑鲈的生长,提高其脾体指数(P＜0.05),然而对大口黑鲈的饲料系数、成活率、肥满度、内脏比指数以及肝体指数等的影响均不显著(P＞0.05);试验前50 d,饲料中添加维生素C能显著提高大口黑鲈血清中溶菌酶的活力(P＜0.05),第60 d,饲料中添加维生素C为2g/kg以上时,能显著提高大口黑鲈血清中溶菌酶活力(P＜0.05);试验前30 d,饲料中添加维生素C能显著提高大口黑鲈血清中超氧化物歧化酶活力(P＜0.05),后30 d大口黑鲈血清中超氧化物歧化酶活力下降;随着饲料中维生素C添加水平的提高,大口黑鲈肝脏中维生素C的积累量显著升高(P＜0.05).试验证明,维生素C能有效地提高大口黑鲈的生长与非特异性免疫能力.

Effect of dietary vitamin C on growth and non- specific immunity in largemouth bass Micropterus salmoides

An experiment was conducted to study the effects of coated vitamin C with different supplementation levels(0,0.5,1,2 and 4 g/kg diet)on growth and non-specific immune response in largemouth bass Micropterus salmoides(initial weight about 19 g) for 2 months.Largemouth bass was stocked into a net cage at a rate of 50 individuals per cage in triplication.The results showed that there were significantly better growth rate and higher spleen-somatic index in the fish fed the diets containing coated vitamin C at high dose(more than 1 g/kg)(P<0.05).However,there were no significant differences in feed conversion rate,survival rate,condition factor,viserosomatic index and hepatosomatic index in the fish in the treatments.During the first 50 days,the fish fed the diets containing vitamin C supplementation had significantly higher serum lysozyme activity(P<0.05).There was significantly higher serum superoxide dismutase(SOD) activity in the fish fed the diets containing vitamin C supplementation(P<0.05) during the first 30 days.During the last 30 days,however,the fish fed the diets containing vitamin C supplementation had significantly lower serum SOD activity.The ascorbic acid concentrations in the largemouth bass hepatopanereas increased significantly with the increase in the diet vitamin C supplementation levels(P<0.05).