烟酸对高精料饲粮肥育肉牛生长性能及血清生化指标的影响

本文旨在研究高精料饲粮中添加烟酸对肥育肉牛生长性能、养分表观消化率和血清生化指标的影响。选择体况良好、体重(402.2±25.4)kg的杂交公牛[西门塔尔()×中国黄牛(♀)]24头,随机分成4组,每组6头牛。Ⅰ组、Ⅱ组、Ⅲ组和Ⅳ组在精料中分别添加200、400、600和800 mg/kg的烟酸(以干物质计),饲粮精粗比85∶15,试验期56 d。结果表明:补饲烟酸对干物质采食量没有显著影响(P>0.05),Ⅳ组的生长性能优于其余3组。Ⅳ组饲粮粗蛋白质、粗脂肪的表观消化率显著地高于其余3组(P<0.05),酸性洗涤纤维表观消化率显著地高于Ⅲ组(P<0.05),中性洗涤纤维表观消化率显著地高于Ⅱ组和Ⅲ组(P<0.05)。烟酸水平对血清葡萄糖、甘油三酯和β-羟基丁酸的浓度无显著影响(P>0.05),Ⅳ组血清非酯化脂肪酸浓度极显著地高于其余3组(P<0.01)。结果提示,高精料饲粮中补饲烟酸可提高肥育肉牛生长性能和养分表观消化率,本试验条件下以精料中添加800 mg/kg的烟酸效果较好。

Effects of Nicotinic Acid on Growth Performance and Serum Biochemical Parameters of Finishing Beef Cattle Fed High Concentrate Diets

The effects of nicotinic acid on the growth performance,nutrient apparent digestibility and serum biochemical parameters of finishing beef cattle fed of high concentrate diets were studied.A total of 24 healthy cross cattle [Simmental()×Chinese yellow cattle(♀)] with initial body weight of(402.2±25.4) kg were randomly allocated into 4 groups with 6 cattle in each group.Cattle in groups Ⅰ,Ⅱ,Ⅲ and Ⅳ were fed concentrate supplemented with nicotinic acid at 200,400,600 and 800 mg/kg(DM basis),respectively.The dietary concentrate to forage ratio was about 85∶15.The experimental period lasted for 56 d.The results showed as follows: there was no significant difference in the dry matter intake of four groups(P>0.05),and the growth performance of group Ⅳ was better than that of the other three groups.The apparent digestibility of crude protein and ether extract of group Ⅳ was significantly higher than that of the other three groups(P<0.05),the apparent digestibility of acid detergent fiber of group Ⅳ was significantly higher than that of group Ⅲ(P<0.05),and the apparent digestibility of neutral detergent fiber of group Ⅳ was significantly higher than that of groups Ⅱ and Ⅲ(P<0.05).The content of serum non-esterified fatty acid of group Ⅳ was significantly higher than that of the other three groups(P<0.01),but there were no significant differences in contents of serum glucose,triglyceride and β-hydroxy-butyrate dehydrogenase(P>0.05).The results indicate that supplementation of nicotinic acid in high concentrate diet can obtain favorable effects on growth performance and nutrient apparent digestibility of finishing beef cattle,and 800 mg/kg is considered to be the optimal level in the concentrate under conditions in this study.