红鳍东方鲀幼鱼赖氨酸需求量的研究

本试验旨在研究红鳍东方鲀幼鱼对饲料赖氨酸的需求量。在基础饲料中分别添加不同水平晶体赖氨酸配制成6种等氮等脂饲料(赖氨酸水平分别为1.65%、2.58%、3.18%、4.01%、4.80%、5.52%)。将体重(13.83±0.63)g红鳍东方鲀幼鱼随机放入18个养殖桶(6个组,每组3个重复,每桶30尾鱼),在室内流水系统中进行67 d的养殖试验。结果表明:随着饲料赖氨酸水平的提高,红鳍东方鲀的特定生长率、饲料效率和蛋白质沉积率均呈先升高后降低的趋势,且当赖氨酸水平为4.80%时达到最高,显著高于1.65%赖氨酸组(P<0.05);1.65%赖氨酸组鱼体粗脂肪含量、肝体比和脏体比最高,显著高于其他组(P<0.05);随着饲料赖氨酸水平的提高,肝脏和血清谷草转氨酶活性呈先升高后降低的趋势,血清高密度脂蛋白胆固醇含量呈逐渐升高的趋势,4.80%和5.52%赖氨酸组显著高于1.65%赖氨酸组(P<0.05)。以特定生长率为评价指标进行二次回归曲线分析,得出红鳍东方鲀幼鱼对饲料赖氨酸需求量为3.83%,占饲料蛋白质的7.66%。

Requirement of Lysine in Juvenile Tiger Puffer(Takifugu rubripes)

The aim of this study was to investigate dietary lysine requirement for tiger puffer Takifugu rubripes.Six isonitrogenous and isoenergetic semi?purified diets were formulated to contain graded lysine levels(1.65%,2.58%,3.18%,4.01%,4.80% and 5.52%).Juvenile tiger pufferinitial body weight(13.83±0.63)g]were randomly assigned to 18 tanks(30 fish per tank and 3 replicate tanks per group)in indoor flow?through and aerated aquaria for 67 days.The results showed as follows:the specific growth rate,feed efficiency and protein deposition rate firstly increased and then decreased with the increase of dietary lysine level,and reached the highest value when experimental diets contained 4.80%lysine,which was significantly higher than that in 1.65%lysine group(P<0.05).The whole body crude lipid content,hepatosomatic index and viscerosomatic index in the 1.65%group was significantly higher than that in other groups(P<0.05).Glutamic oxaloacetic transaminase activity in liver and serum increased first and then decreased with the increase of dietary lysine level.Serum high density lipoprotein cholesterol content increased with the increase of dietary lysine level,which was significantly higher in the 4.80%and 5.52%groups than that in 1.65%group(P<0.05).Second?order polynomial regression analysis on the basis of specific growth rate(SGR)indicates that the optimum di?etary lysine requirements of tiger puffer is estimated to be 3.83%of diet(7.66%of dietary protein).