饲料脂肪水平对褐菖鲉生长、肠道消化酶及主要脂代谢酶活力的影响

研究了不同脂肪水平饲料对褐菖鲉（Sebastiscusmarmoratus）生长、肠道消化酶及肝脏中主要脂代谢酶活力的影响，试验选用平均体质量为（27．56±0．19）g的褐菖鼬幼鱼225尾，随机分成5个组，分别投喂脂肪水平为6．1％、9．5％、12．4％、15．1％和18．5％的饲料，试验周期为60d。结果表明，1）褐菖铀的特定生长率和肥满度呈先升后降的趋势，在脂肪水平12．4％时达到最大（P〈0．05），饵料系数则相反，呈先降后升的趋势，肝体指数随脂肪水平的升高而增大（P〈0．05），成活率在各组问没有显著差异；2）鱼体肠道脂肪酶活力呈上升趋势（P〈0．05），胃蛋白酶与淀粉酶活力在各组之间没有显著差异；3）褐菖鲉的脂肪酸合成酶活力呈先升后降的趋势（P〈0．05），脂蛋白酶活力和肝酯酶活力也呈上升趋势，但各组间差异不显著。根据特定生长率与饲料脂肪水平的回归曲线计算得出，褐菖鲉幼鱼最适脂肪需求量为12．72％。

Effects of dietary lipid levels on growth,intestinal digestive enzyme and main lipid metabolic enzyme activities of Sebastiscus marmoratus

We evaluated the effects of dietary lipid levels on the growth, intestinal digestive enzyme and main lipid metabolism enzyme activities of Sebastiscus marmoratus. Two hundred and twenty-five juveniles with average initial body weight of （27. 56 ±0. 19） g were randomly divided into 5 groups fed with diets at lipid levels of 6. 1% , 9. 5%, 12.4% , 15.1% and 18.5%, respectively. The ex- periment lasted for 60 d and the results show that： 1 ） The specific growth rate （SGR） and condition factor （CF） first increased then decreased and reached the maximum values in diet C （ 12.4% ） （ P 〈 0. 05 ） , while the feed conversion rate （FCR） showed a contrary trend. The hepatosomatic index （HIS） increased with increasing dietary lipid level （P 〈 0.05 ）. No significant difference was found in the survival among all diets ; 2） The lipase activity of intestinal tract increased with increasing dietary lipid level （ P 〈 O. 05 ）. No sig- nificant difference was found in the pepsin and amylase activities among all diets; 3 ） The fatty acid synthetase activity first increased then decreased from 6. 1% to 18. 5% （P 〈 0. 05 ）. The activities of lipoprotein lipase and hepatic lipase increased but no significant difference was found among all diets. According to the regression curve of SGR and dietary lipid level, the suitable dietary lipid levelfor S. marmoratus should be 12. 72%.