黄斑蓝子鱼幼鱼对蛋白质和脂肪适宜需要量的研究

Optimal levels of protein and lipid in diets for rabbitfish Siganus canaliculatus juvenile

采用酪蛋白为蛋白源、鱼油为脂肪源,配制脂肪含量为8%而蛋白水平分别为24%、28%、32%、36%和40%,以及蛋白含量为32%而脂肪水平分别为3%、6%、9%和12%的9种配合饲料,对黄斑蓝子鱼（Siganus canaliculatus）幼鱼开展8周的生长试验,以研究其对蛋白质和脂肪的适宜需要量。结果显示,饲料中的蛋白质和脂肪含量对蓝子鱼的生长性能、饲料利用率及鱼体生化成分等都有一定的影响。蛋白水平过高（40%）或过低（24%）的饲料组鱼的生长效果较差;32%蛋白水平组鱼的增质量率和蛋白质效率最好、且显著高于其他各组,而饲料系数显著低于其他各组。鱼体的蛋白质含量随着饲料蛋白水平的增加而呈上升趋势,但水分、粗脂肪和灰分的含量不受影响。3%~9%脂肪水平组鱼的增质量率、饲料系数和蛋白质效率相互间无显著差异,但它们的增质量率及蛋白质效率显著高于12%脂肪水平组鱼,而饲料系数正好相反。肝体指数和鱼体脂肪含量随着饲料脂肪水平的增加而升高,但鱼体的蛋白质和水分含量受饲料脂肪水平的影响不大。3%脂肪水平组鱼的成活率较低。根据增质量率及蛋白质效率与饲料蛋白水平的二次回归分析,获得蓝子鱼幼鱼对蛋白质的适宜需要量为29.01%~34.37%;综合考虑上述指标,认为蓝子鱼幼鱼饲料中脂肪的适宜添加量为6%~9%。

With casein as the protein source and fish oil as the lipid source,nine formulated diets with 8% lipid but different levels of protein（24%,28%,32%,36% and 40%） or 32% protein but different levels of lipid（3%,6%,9% and 12%） were made and used to feed Siganus canaliculatus juveniles for 8 weeks,to determine the optimum requirements for protein and lipid in diets.The results showed that dietary contents of protein and lipid affected the growth performance,feed utilization,and biochemical composition of fish.Fish fed with diets of the highest（40%） or lowest（24%） level of protein displayed the worst growth performance,while those fed with diet of 32% dietary protein showed best performances,including the highest weight gain（WG） and protein efficiency rate（PER）,and the lowest feed conversion rate（FCR）,which were significantly different with any other dietary groups.Fish protein content was notably increased with the increase of dietary protein levels,but fish moisture or crude lipid was not significantly affected.WG,PER or FCR showed no significant difference among 3% ~ 9% dietary lipid groups.However,WG in 3% ~ 9% lipid groups,as well as PER in 6% ~ 9% dietary lipid groups,were significantly higher than that in 12% dietary lipid group.Reverse result was observed for FCR.Both hepatosomatic index（HSI） and fish lipid content were increased with the increase of dietary lipid levels,however,fish protein and moisture were not affected.In addition,3% dietary lipid group showed low survival rate.According to the quadratic regression analysis of WG or PER with dietary levels of protein,the optimal requirement of protein in diets of S.canaliculatus juveniles was 29.01%~34.37%;Considering all the indexes mentioned above,the optimum addition level of lipid in S.canaliculatus diet was 6%~9%.