饲粮烟酸水平对产蛋高峰期山麻鸭产蛋性能、蛋品质和脂类代谢的影响

Effects of Dietary Niacin Levels on Laying Performance,Egg Quality and Lipid Metabolism of Shanma Ducks during Laying Peak Period

本试验旨在探讨饲粮添加不同水平烟酸对产蛋高峰期山麻鸭产蛋性能、蛋品质和脂类代谢的影响。试验采用单因素完全随机设计,将1050只体重一致的24周龄福建龙岩山麻鸭随机分为7个组,每组6个重复,每个重复25只鸭。试验采用玉米-豆粕型基础饲粮,各组饲粮烟酸添加水平分别为0(对照)、15、30、45、60、75和90 mg/kg。试验期为16周。结果表明:1)饲粮烟酸水平对山麻鸭产蛋性能和蛋品质无显著影响(P>0.05)。2)随着饲粮中烟酸添加水平的提高,蛋黄中脂肪含量逐渐下降(P<0.05),全蛋脂肪比例也逐渐下降(P<0.05),同时蛋黄中游离脂肪酸含量逐渐升高(P<0.05);其中,与对照组相比,饲粮添加75和90 mg/kg烟酸显著降低蛋黄中脂肪含量(P<0.05),饲粮添加75 mg/kg烟酸显著降低全蛋脂肪比例(P<0.05),饲粮添加45、60、75和90 mg/kg烟酸显著提高蛋黄中游离脂肪酸含量(P<0.05)。3)饲粮烟酸水平对血浆尿酸、胆固醇、甘油三酯和低密度脂蛋白胆固醇含量均无显著影响(P>0.05)。4)当饲粮烟酸添加水平为15 mg/kg时,肝脏胆固醇含量显著高于其他组(P<0.05),同时肝脏脂肪酸合成酶(FAS)、固醇调节元件结合蛋白1(SREBP1)及载脂蛋白A1(ApoA1)的mRNA相对表达量最高。综上所述,在玉米-豆粕型基础饲粮中添加烟酸对山麻鸭产蛋性能和蛋品质无显著提升效果,但饲粮烟酸添加水平超过75 mg/kg时,可以促进脂肪在蛋中的分解,降低蛋黄中脂肪含量。

The aim of this study was to investigate the effects of different dietary levels of niacin on laying performance,egg quality and lipid metabolism of Shanma ducks during laying peak period.Using a single factor completely randomized design,a total of 1050 Fujian Longyan Shanma ducks of 24-week-old with the same body weight were randomly divided into 7 groups with 6 replicates per group and 25 ducks per replicate.The corn-soybean meal type basal diet was used in the experiment,and the dietary niacin supplemental levels of each group were 0(control),15,30,45,60,75 and 90 mg/kg,respectively.The trial lasted for 16 weeks.The results showed as follows:1)dietary niacin levels had no significant effects on laying performance and egg quality of Shanma ducks(P>0.05).2)With the dietary niacin supplemental level increasing,the fat content in yolk was gradually decreased(P<0.05),the fat proportion in the whole egg was also gradually decreased(P<0.05),and the free fatty acid content in yolk was gradually increased(P<0.05).Compared with the control group,dietary supplementation of 75 and 90 mg/kg niacin significantly decreased the fat content in egg yolk(P<0.05),dietary supplementation of 75 mg/kg niacin significantly decreased the fat proportion in whole egg(P<0.05),and dietary supplementation of 45,60,75 and 90 mg/kg niacin significantly increased the free fatty acid content in yolk(P<0.05).3)Dietary niacin levels had no significant effects on plasma contents of uric acid,cholesterol,triglyceride and low-density lipoprotein cholesterol(P>0.05).4)When the dietary niacin supplemental level was 15 mg/kg,the liver cholesterol content was significantly higher than that in the other groups(P<0.05),and the relative mRNA expression levels of liver fatty acid synthase(FAS),sterol regulatory element binding protein 1(SREBP1)and apolipoprotein A1(ApoA1)were the highest.In conclusion,the dietary supplementation of niacin in the corn-soybean meal type basal diet has no significant effects on the laying performance and egg quality of Shanma ducks,but when the dietary niacin supplemental level exceeds 75 mg/kg,it can promote the lipolysis in eggs and reduce the fat content in egg yolk.