本试验以猪油作为日粮的主要能量来源并添加盐酸二甲双胍，研究其对产蛋鸡脂质代谢和生产性能的影响。选取72只褐壳罗曼蛋鸡（30周龄），随机分为3个组，每组8个重复，每个重复3只鸡。试验分组如下：对照组（玉米-豆粕型日粮）、猪油组(大豆分离蛋白-猪油型日粮)和猪油+盐酸二甲双胍组（大豆分离蛋白-猪油型日粮+盐酸二甲双胍）。所有产蛋鸡每日消耗的营养元素量都相同，每只鸡每天盐酸二甲双胍添加量为0.55 g，试验持续8周。结果表明，与对照组相比，猪油组和猪油+盐酸二甲双胍组的产蛋率分别下降了51.5%（P<0.01）和59.9%（P<0.01）；猪油组的肝脂水平显著升高(P<0.05)，但添加盐酸二甲双胍对肝脂水平没有显著影响（P>0.05）；猪油+盐酸二甲双胍组蛋黄粗脂肪（P<0.01）和总胆固醇(P<0.05)含量显著或极显著降低；猪油+盐酸二甲双胍组血浆中载脂蛋白B和极低密度脂蛋白含量以及卵黄生成素受体基因表达水平显著降低(P<0.05)；猪油组的蛋黄中油酸含量极显著提高(P<0.01)，而亚油酸的含量则极显著降低(P<0.01)。由此得出：1)添加猪油加重了产蛋鸡脂肪肝的形成，进而降低了生产性能；2)添加猪油会改变蛋黄中脂类组成并可降低不饱和脂肪酸含量；3)盐酸二甲双胍对脂质过度沉积的负面影响并没有缓解作用，但可以降低蛋黄总胆固醇含量。

This study was to investigate the effects of lard as main dietary energy source along with metformin supplementation on lipid metabolism and production performance of laying hens. A total of 72 brown-shell Roman laying hens with the age of 30-week were randomly assigned to 3 dietary groups. Each group had 8 replicates with 3 hens each. Experimental groups were as follows: control group (corn-soybean meal diet), lard group (soybean isolated protein-lard diet) and lard+metformin group (soybean isolated protein-lard diet plus metformin). All layers consumed the same amount of nutrients per day. Metformin was fed at 0.55 g per day per hen. The experiment lasted for 8 weeks. Results showed as follows: compared with the control group, laying rate in lard group and lard+metformin group was significantly decreased by 51.5% (P<0.01) and 59.9% (P<0.01), respectively; liver fat level in lard group was significantly increased (P<0.05) while metformin supplementation had no effects on liver fat level (P>0.05); plasma apolipoprotein B and very low density lipoprotein contents and ovary oocyte vitellogenesis receptor expression level in lard+metformin group were significantly decreased (P<0.05); yolk crude fat (P<0.01) and triglyceride (P<0.05) contents in lard+metformin group were significantly decreased; yolk oleic acid content in lard group was significantly increased (P<0.01), however, yolk linoleic acid content in lard group was significantly decreased (P<0.01). In conclusion, 1) lard supplementation can aggravate fatty liver formation and depress production performance for laying hens; 2) lard supplementation can alter lipid composition of yolk and decrease unsaturated fatty acid content; 3) metformin supplementation can not alleviate the negative effects of over-lipid deposition, but can decrease yolk total cholesterol content. ［Chinese Journal of Animal Nutrition, 2010，22（5）:1382-1389］