以猪油为日粮能量来源并添加盐酸二甲双胍对产蛋鸡脂质代谢和生产性能的影响

Effects of Lard as Dietary Energy Source along with Metformin Supplementation on Lipid Metabolism and Production Performance of Laying Hens

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0.55g,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.