L-肉碱对草龟摄食生长和身体组成的影响

Effects of L-carnitine on feeding growth and body composition of Chinese pond turtles(Chinemys reevesii)

为研究饲料中添加不同梯度的L-肉碱对草龟(Chinemys reevesii)摄食生长和身体组成的影响,试验在基础饲料中分别添加0、100、200、300、400 mg/kg和500 mg/kg的L-肉碱配制成6种试验膨化饲料,分别投喂6个试验组(分别用L0、L1、L2、L3、L4、L5表示,其中L0为对照组)的草龟,每组设8个重复缸,每个重复缸内养殖10只龟,养殖试验期8周。结果表明:试验L2、L1组的特定生长率和相对生长率较对照组分别提高8.61%、8.13%、15.54%、14.79%(P<0.05);摄食率、总消化率和饵料系数在各组之间差异未达显著水平(P>0.05)。草龟龟体的水分、粗蛋白质、粗脂肪、粗灰分含量和能值均无显著性差异(P>0.05);肝脏的粗脂肪含量差异显著,其中L3组的肝脏粗脂肪含量较对照组降低25.72%(P<0.05)。综上,添加L-肉碱可显著提高草龟的生长性能,根据特定生长率与L-肉碱添加剂量的效应关系,通过非线性回归可以得出草龟配合饲料中L-肉碱的适宜添加量为132.4 mg/kg。

In this experiment,the effects of dietary L-carnitine on feeding growth and body composition of Chinese pond turtles were studied,and the appropriate dietary L-carnitine supplemental amount was discussed.Six experimental diets were formulated by adding 0,100,200,300,400 mg/kg and 500 mg/kg L-carnitine into the basal diet,respectively.Six experimental groups were set(they were represented by L0,L1,L2,L3,L4 and L5,of which L0 was the control group and the others were the carnitine supplemental groups),with 8 replicates in each group,and 10 turtles were cultured in each replicate tank.The experiment lasted eight weeks.The results showed that the specific growth rate and relative growth rate in L2 and L1 groups were 8.61%,8.13%,15.54%and 14.79%higher than those in the control group,respectively.There were no significant differences in dry matter digestibility,feeding rate and feeding coefficient among all groups(P>0.05).There were no significant differences in moisture,crude protein,crude lipid and crude ash contents among the experimental groups(P>0.05).Liver crude lipid content in L3 group was 25.72%lower than that in the control group.In conclusion that adding L-carnitine could significantly improve the growth performance of Chinese pond turtles,and has a positive effect on preventing fatty liver.According to the effect relationship between specific growth rate and L-carnitine supplemental dose,the optimal supplemental level of L-carnitine in the compound feed of Chinese pond turtles was 132.4 mg/kg through nonlinear regression.