【摘要】 以酪蛋白和明胶为蛋白源,七水硫酸锌为锌源,在基础饲料中分别添加锌0,50,100,150,200,400mg/kg,制成6种含有不同锌水平的精制饲料(19.95,71.06,118.50,174.00,226.10和411.20mg/kg),投喂初始体重为(62.89±0.51)g的星斑川鲽幼鱼66d,研究饲料锌水平对星斑川鲽幼鱼生长、体成分、组织锌积累及抗氧化能力的影响。结果表明,随着饲料锌水平的增加,星斑川鲽的增重率(WGR)显著升高(P<0.05),在174.00mg/kg锌饲料组达最大值,而锌水平高于174.00mg/kg时,其增重率和特定生长率(SGR)变化不显著(P>0.05),SGR和WGR的变化趋势相同,且SGR的最大值及饲料系数(FCR)的最小值均出现在174.00mg/kg锌饲料组;全鱼营养成分各处理组间均无显著差异(P>0.05),锌添加量为0mg/kg饲料组的肌肉脂肪含量显著高于其它各组(P<0.05);411.20mg/kg锌饲料组的全鱼、脊椎骨和肌肉中锌积累量显著高于其它各组(P<0.05),当饲料锌水平为118.50～411.20mg/kg时,全鱼、脊椎骨和血清中锌积累量显著高于19.95mg/kg和71.06mg/kg锌饲料组(P<0.05),饲料锌水平对肝脏锌含量无影响(P>0.05);血清总抗氧化能力和超氧化物歧化酶(SOD)活力随着饲料锌水平的增加均显著升高(P<0.05),而锌水平高于174.00mg/kg时,上述指标维持在相对稳定水平。综上所述,饲料中添加适量锌可以显著提高星斑川鲽的生长性能和组织锌积累量、增强机体的抗氧化功能。以WGR为评价指标,折线回归分析表明,星斑川鲽幼鱼对饲料中锌的最适需要量为167.88mg/kg。更多还原

【Abstract】 An experiment was conducted to investigate the effects of dietary zinc on growth performance, body composition,tissue zinc accumulation and antioxidation of juvenile starry flounder ( Platichthys stellatus) with zinc sulfate( ZnSO4·7H2O) as zinc source,by using a purified diet based on casein-gelatin as the protein sources. The basal diet was supplemented with 0,50,100,150,200 and 400 mg zinc per kg diet respectively and juvenile starry flounder[initial weight( 62. 89 ±0. 51) g]were fed 6 purified diets containing graded levels of zinc( 19. 95,71. 06,118. 50,174. 00,226. 10 and 411. 20 mg /kg) respectively for 66-day experimental period. The results showed that weight gain rate( WGR) increased significantly with increasing dietary zinc level( P <0. 05) ,but no significant differences were observed among the juveniles fed the diets with equal to or higher than 174. 00 mg /kg of dietary zinc( P >0. 05) ,special growth rate( SGR) and WGR followed the same trend. The fish got the highest WGR,SGR and the lowest feed conversion rate( FCR) in the treatment with 174. 00 mg /kg of dietary zinc. No significant differences were observed in whole body composition among dietary treatments( P >0. 05) ,the fat deposition in muscle of zinc supplementation of 0 mg /kg group was significantly higher than those in the other groups( P < 0. 05) . When the juveniles were fed the diet with 411. 20 mg /kg of dietary zinc,the zinc accumulation contents in the whole body,vertebrae and muscle were significantly higher than those in the other groups( P <0. 05) . When the juveniles were fed 118. 50 -411. 20 mg /kg of dietary zinc,the zinc accumulation contents in whole body,vertebrae and serum were significantly higher than 19. 95 mg /kg group and 71. 06 mg /kg group( P < 0. 05) ,however,the liver zinc contents remained comparatively stable among all groups( P > 0. 05) . Serum total antioxidant capacity and superoxide dismutase ( SOD ) activity increased significantly with increasing dietary zinc level ( P < 0. 05) ,and then leveled off when the juveniles were fed the diets with equal to or higher than 174. 00 mg /kg of dietary zinc. In conclusion,it could improve growth performance and tissue zinc accumulation,and enhance antioxidation function by adding proper dose of zinc in basic diet of juvenile starry flounder. Broken-line regression analysis showed that the optimum dietary zinc requirement for juvenile starry flounder,using WGR as response criteria,was 167. 88 mg /kg of dietary zinc.更多还原