饲料脂肪水平对点篮子鱼生长和体成分的影响

通过添加鱼油和豆油(1∶1)等比例混合油,配制6组脂肪水平分别为4.16%、7.42%、10.68%、14.20%、16.56%、19.62%的等氮饲料,标号依次为L1、L2、L3、L4、L5、L6。以初始体重28.09±0.60g的点篮子鱼(Siganus guttatus)为实验对象,经过八周的饲养,研究饲料脂肪水平对点篮子鱼生长及体成分的影响。结果表明:增重率(WG)、特定生长率(SGR),L3和L4组显著高于其它四组(P<0.05),且两指标均随饲料中脂肪含量的增加表现出先升后降的趋势。全鱼、肌肉及肝脏粗脂肪含量随饲料脂肪水平的升高而升高。全鱼粗蛋白含量L1与L6组最低,显著低于其它四组(P<0.05);肌肉蛋白、水分及灰分与饲料脂肪水平没有显著相关性(P>0.05)。肝脏水分含量随着饲料脂肪水平的升高而降低。综合点篮子鱼生长及鱼体成分分析,点篮子鱼饲料中脂肪适宜添加量为10.68%～14.20%,以增重率为指标,通过二次回归分析得出,点篮子鱼饲料中脂肪的最适添加量为13.94%。

Effects of dietary lipid level on growth and body composition of Siganus guttatus

A growth trial was conducted to evaluate the effects of dietary lipid level on growth performance and body composition of Siganus guttatus.Six isonitrogenous diets with increasing lipid levels of 4.16%(L1),7.42%(L2),10.68%(L3),14.20%(L4),16.56%(l5),19.62%(L6) were fed to duplicate groups of 28.09±0.60g fish for 8 weeks and weight gain was recorded.At the end of the feeding experiment,fish fed with 10.68% lipid diet and 14.20% lipid diet showed optimal growth performance(P<0.05).Lipid content of whole body,muscle and liver increased in parallel with the increase in dietary lipid levels.The whole body protein content of L1 and L6 were the lowest,while there were no significant differences in other four groups(P>0.05).Protein content,moisture content,and ash content of the muscle were not significantly affected by dietary lipid levels.Moisture content of liver decreased with the increase of dietary lipid levels.Results showed that the optimum dietary lipid requirement for Siganus guttatus was 10.68%-14.20%.Based on a second-order polynomial regression analysis of lipid level against weight gain rate,the optimum dietary lipid level for Siganus guttatus was 13.94%.