本试验旨在研究饲粮中添加L-肉碱对产蛋鸡生产性能、蛋品质和脂质代谢的影响。选用576只产蛋率和体重相近、健康的53周龄海兰褐产蛋鸡，随机分成6个处理，每个处理6个重复，每个重复16只鸡。6种试验饲粮分别添加0、25、50、100、200或400 mg/kg L-肉碱，试验期6周。结果表明：1）饲粮中添加L-肉碱未显著影响产蛋率、日采食量、平均蛋重和料蛋比（P>0.05）；2）饲粮中添加L-肉碱显著提高了试验第3周时鸡蛋的蛋白高度和哈夫单位（P<0.05），其中以25 mg/kg组最佳；添加L-肉碱还提高了试验第6周时鸡蛋蛋壳强度（P<0.05），其中25 mg/kg组和200 mg/kg组较佳；饲粮中添加L-肉碱有提高试验第3周和第6周蛋黄颜色的趋势（P=0.07，P=0.06），对蛋壳厚度和蛋形指数影响不显著（P>0.05）；3）饲粮中添加L-肉碱显著降低了产蛋鸡血清中甘油三酯和低密度脂蛋白胆固醇含量及试验第6周总胆固醇和高密度脂蛋白胆固醇含量（P<0.05）。由此可知，饲粮添加L-肉碱不影响产蛋鸡生产性能，但可改善鸡蛋品质，降低血脂；综合考虑成本和鸡蛋品质，以饲粮中添加L-肉碱25 mg/kg为宜。

The objective of this study was to investigate the effects of dietary L-carnitine on performance, egg quality and lipid metabolism in laying hens. A total of five hundred and seventy-six 53-week-old healthy Hyline laying hens with similar egg production rate and body weight were chosen and divided into 6 groups with 6 replicates per group and 16 hens per replicate. The diets were the corn-soybean meal based diets with different levels of L-carnitine (0, 25, 50, 100, 200 and 400 mg/kg). The experiment lasted for 6 weeks. The results showed as follows: 1) L-carnitine supplementation had no significant effects on egg production rate, average egg weight, daily feed intake, and ratio of feed to egg weight (P>0.05); 2) the supplementation of L-carnitine in the diet significantly increased the albumen height and Haugh unit at week 3 of the experiment (P<005), and 25 mg/kg group was the best among them; the supplementation of L-carnitine in the diet significantly increased the eggshell strength at week 6 of the experiment (P<0.05), and 25 and 200 mg/kg groups were better than the others; there was a tendency to increase the yolk color at week 3 (P=0.07) and week 6 (P=0.06) of the experiment, but no significant effects were found on eggshell thickness and egg shape index (P>0.05); 3) the supplementation of L-carnitine in the diet significantly decreased the contents of TC and HDLC at week 6 and the contents of TG and LDLC in serum (P<0.05). In conclusion, the supplementation of L-carnitine in the diet can improve the egg quality and lipid metabolism in laying hens, meanwhile, it has no significant effects on performance. According to the egg quality and the cost of feed, it is recommended that 25 mg/kg L-carnitine should be added to the laying hen diet.［Chinese Journal of Animal Nutrition，2011，23（4）：640 -646］