青海湖裸鲤幼鱼蛋白质需要量研究

Dietary Protein Requirement of Juvenile Gymnocypris przewalskii in Qinghai Lake

试验旨在确定青海湖裸鲤幼鱼蛋白质需要量(初始体重为:16.43g),以实用饲料配方为基础,设计7个蛋白质水平(31%、33%、35%、37%、39%、41%和43%)的试验饲料,每组饲料投喂3个重复。养殖过程在循环水系统中进行。结果表明,随着饲料蛋白质水平的增加,青海湖裸鲤幼鱼特定生长率呈现先显著上升(P<0.05)后平稳的趋势(P>0.05),饲料系数呈现下降趋势,但各处理组间无显著差异(P>0.05)。青海湖裸鲤幼鱼血清谷草转氨酶活性及总胆固醇和甘油三酯含量随着饲料蛋白质水平的增加而增加(P<0.05),而血清尿素氮含量随着饲料蛋白质水平的增加而降低(P<0.05)。根据特定生长率结果,由折线模型拟合得出青海湖裸鲤幼鱼蛋白质需要量为37.67%。

An 8week feeding trial was conducted to estimate the dietary protein requirement of juvenile Gymnocypris przewalskii（initial weight 16.43g）.Practical basal diets were used and seven diets were formulated to contain graded levels of protein（31%,33%,35%,37%,39%,41% and 43%）.Each diet was fed to triplicate groups of fish in a recirculating rearing system.Results showed that the specific growth rate（SGR）increased significantly with the increasing dietary protein levels（31~37%;P〈0.05）and then no further increase was detected（37~43%;P〉0.05）.Feed conversion ratio of fish showed decreasing trend with increase of dietary protein levels,but no significant difference was found among treatments（P〉0.05）.Glutamic-oxalacetic transaminase（AST）activity,total cholesterol and triglyceride contents in serum were significantly increased but serum urea nitrogen content was decreased with increase of dietary protein levels（P〈0.05）.Based on the SGR data,dietary protein requirement of juvenile Gymnocypris przewalskii was 37.67% by broken-line regression analysis.