饲料中非蛋白能源物质对黄颡鱼幼鱼生长及生理生化指标的影响

Effects of dietary non-protein energy sources on growth,physiology and biochemistry of yellow catfish(Pelteobagrus fulvidraco)

探讨了饲料中不同糖脂比(CHO∶L)对黄颡鱼(Pelteobagrus fulvidraco)幼鱼生长性能、体组成和脂肪代谢的影响。试验采用6组等氮等能的半纯和饲料投喂黄颡鱼幼鱼,其CHO∶L分别为1.11、1.67、2.45、3.63、5.58和9.50,网箱养殖8周。研究结果表明,饲料中不同CHO∶L对幼鱼成活率无显著影响(P>0.05)。增质量率、特定生长率、蛋白质效率、氮保留率和能量保留率均随着CHO∶L的升高呈现先升高后降低的趋势(P<0.05),且均在CHO∶L为3.63时达最大值。肝体比、脏体比、全鱼水分含量、肝糖原和肌糖原含量均随饲料CHO∶L的升高而显著升高(P<0.05),全鱼、肝脏和肌肉脂肪含量显著降低,而胴体率、肥满度、全鱼蛋白质和灰分含量则均无显著变化。胃、肠道淀粉酶活性随着饲料CHO∶L的升高显著升高,脂肪酶活性显著降低,蛋白酶活性则呈现先升高后降低的趋势。此外,血浆总胆固醇和甘油三酯含量以及肝脏脂蛋白脂酶、肝脂酶和总脂酶活性均随着CHO∶L的升高显著降低,而游离脂肪酸含量则无显著变化。对增质量率和饲料中糖与脂肪水平分别进行回归分析,得出黄颡鱼幼鱼饲料的适宜糖和脂肪水平分别为29.16%和7.94%,最适CHO∶L为3.67。

This study aimed to investigate the effects of dietary carbohydrate/lipid （ CHO ： L） ratios on growth performance, body composition and lipid metabolism of yellow catfish （ Pelteobagrus fidvidraco ）. Fish were fed with six isonitrogenous and isoenergetic diets（ the CHO ：L ratios of 1.11,1.67,2.45,3.63,5.58,9.50） in cages for 8 weeks. The results indicated that survival rate showed little difference （P〉0.05）among all the treatments. The best weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio and nitrogen and energy retention efficiency were all observed in fish fed with the diet with a CHO ： L ratio of 3.63. Hepatosomatic index, viscerosomatic index, whole-body moisture content, and liver and muscle glycogen contents all increased significantly（P〈0. 05 ）as dietary CHO：L ratios increased, while lipid contents of whole-body, liver and muscle all decreased significantly（P〈0.05 ）with increasing CHO：L ratios. Dressout percentage, condition factor, whole-body protein and ash contents showed little difference（P〉0.05 ）among all the treatments. Contrary to lipase activities, stomach and intestine amylase activities increased significantly （ P〈0. 05 ） as dietary CHO ： L ratios increased. The stomach protease activities increased significantly （ P〈 0.05 ） as dietary CHO ： L ratios ranged from 1.11 to 3.63, hut decreased significandy with the further increasing CHO ： L ratios. In addition, plasma lipid contents,lipoproteinlipase and hepatic lipase all decreased significantly as dietary CHO：L ratios increased（ P〈 0.05 ）, while plasma non-esterified fatty acid levels showed little difference （P〉0.05）. Based on the second-order regression analysis of weight growth ratio,the optimal dietary carbohydrate and lipid contents for yellow catfish were 29.16% and 7.94% ,respectively, with a corresponding dietary CHO ：L ratio of 3.67.