The effects of L-carnitine on growth performance, body composition and blood parameters for juvenile Japanese flounder {Paralichthys olivaceus) with initial body weight of 10.30 ?0.12 g were investigated. The juveniles were fed with diets that supplied with Z-carnitine at 0, 300, 600, 900, 1 200 and 1 500 mg/kg diet. The results showed that juveniles fed with the diet added with 1 200 mg/kg I-carnitine got significant rise in body weight and special growth rate in contrast to that in control group, and the feed conversion ratio in this group got significantly lower than that in control group (P<0.05). The hepato-pancreas index decreased with the L-carnitine level increased, and when the content of I-carnitine was 900-1500mg/kg, there were significant differences compared with the control group(P<0.05). Condition factor and survival rate were not affected by supplemented with i-carnitine(P>0.05). Crude lipid of muscle and liver were negative correlation with supplemented with Z-carnitine, and there were significant differences compared with the control group (P< 0.05), when the i-carnitine content was 1 200 - 1 500 mg/kg. Protein content of muscle was positive correlation with supplemented with Z,-carnitine, but there were no significant differences between the groups (P> 0.05). Glutamate-oxaloacetate transaminase (AST), total cholesterol (CHOL), triglyceride (TG) and blood urea nitrogen (BUN) that supplemented with 1 200 mg/kg L-carnitine were significantly lower than that of the control group (P<0.05). Compared with the control group, the blood glucose of the group that containing Z,-carnitine increased, and that of the group adding 1 200 mg/kg L-carnitine increased by 41.6% (P < 0.05). There was no significant effect in total protein, low density lipoprotein and high density lipoprotein levels at all treatments (P>0.05), but the content of total protein and low density lipoprotein was descended and the content of high density lipoprotein was promoted, according to the increased dietary I-carnitine level. In conclusion, under the condition of this experiment, adding I-carnitine will promote the growth parameters of Japanese Flounde (Paralichthys olivaceus) and reduce crude lipid content of fish, at the same time, the optimal dietary L-carnitine level was estimated to be 1200 mg/kg.%研究0、300、600、900、1 200、1 500 mg/kg 6个L-肉碱添加水平对牙鲆(Paralichthys olivaceus)幼鱼生长、生化组成和血液指标的影响.结果表明:添加量为1 200 mg/kg的处理组牙鲆幼鱼的增重率和特定生长率显著提高,饲料系数显著降低(P＜ 0.05)；随着饲料中L-肉碱含量的增加,肝指数呈现下降趋势,且在添加量为900～1 500 mg/kg时,各组较对照组差异显著(P＜0.05)；饲料中添加L-肉碱显著降低各实验组脏体比(P＜0.05),而对各处理组间存活率和肥满度均无影响(P＜0.05)；肌肉和肝脏中的脂肪含量与L-肉碱添加量呈负相关,当添加量为1 200～1 500 mg/kg时,较对照组差异显著(P＜0.05)；肌肉中的蛋白含量与L-肉碱添加量呈正相关,但各组差异不显著(P＜0.05)；饲料中添加L-肉碱降低血清中的谷草转氨酶、胆固醇、甘油三酯和尿素氮含量,且添加量1 200 mg/kg组各指标含量均显著低于对照组(P＜0.05)；各处理组的血糖含量较对照组均有所增加,其中I 200 mg/kg组血糖含量较对照组提高41.6％(P＜0.05)；血清中总蛋白和低密度脂蛋白均随着L-肉碱添加量的增加而呈下降趋势,高密度脂蛋白却得以提升,但差异均不显著(P＜0.05).分析认为,在本实验条件下,饲料中添加L-肉碱可促进牙鲆幼鱼生长,且降脂效果显著.建议L-肉碱最适添加量为1200 mg/kg.
展开▼
