烟酸对高温环境中奶牛生产性能和血清生化指标的影响

Effects of Supplemental Niacin on Performance and Serum Biochemical Parameters of Lactating Dairy Cows in Hot Environment

本试验旨在研究烟酸对高温环境中奶牛生产性能和血清生化指标的影响。试验选用3头泌乳早期的中国荷斯坦牛,采用3×3拉丁方设计。在基础日粮中分别添加0、6、12 g/d烟酸,试验期为75 d。结果表明:(1)添加烟酸对热应激奶牛直肠温度和呼吸频率无显著影响(P>0.05)。(2)添加6、12 g/d烟酸可使产奶量分别提高13.20%(P<0.05)、9.39%(P<0.05),而4%标准乳量无显著差异(P>0.05);添加烟酸不影响乳蛋白和乳脂率(P<0.05)。(3)添加烟酸使血清胆固醇含量降低,但未达显著水平(P>0.05);添加烟酸6、12 g/d使血糖含量提高37.89%(P<0.05)、51.93%(P<0.05),但两添加组之间无显著差异(P>0.05);添加烟酸12 g/d可显著降低奶牛血清尿素氮含量(P<0.05);添加6、12 g/d烟酸使游离脂肪酸含量降低23.89%(P<0.01)、10.39%(P<0.01)。综合分析试验奶牛的生产性能和血清生化指标变化,夏季给奶牛补饲烟酸有助于缓解热应激,适宜的添加量为6 g/d。

An experiment was conducted using three Chinese Holstein cows in early lactation under hot environment, in a 3 × 3 Latin square design, to determine the effects of the basal diets supplemented with 0, 6, 12 g/d niacin each cow as control group,group B,group C on performance and serum biochemical parameters. The results showed 1） supplemental niacin had no significant effect on the rectal temperature and respiratory rate （P〉0.05）; 2） compared with control group, milk yield of group B and C was increased by 13.20% （P〈0.05）, 9.39% （P〈0.05） respectively, but 4% fat corrected milk yield was not significantly influenced （P〉0.05） ; dietary niacin had no effect on milk fat and protein percentage （P〉0.05） ; 3） compared with control group, the content of serum cholesterol in test groups decreased （P〉0.05） ; the content of serum glucose of group B and C increased by 37.89% （P〈0.05） and 51.93% （P〈0.05） respectively, there was no significant difference between group B and C （P〉0.05） ; the content of serum urea nitrogen decreased significantly at the niacin level of 12 g/d （P〈0.05） ; the content of serum triglyceride was no significant difference between the treatments of supplemental niacin and the control group （P〉0.05）; the content of free fatty acid of group B and C decreased by 23.89% （P〈0.01）, 10.39% （P〈0.01） respectively. As performance and serum biochemical parameters were concerned,niacin supplementation with 6 g/d in the ration of lactating cows had the best effect and released the effect of heat stress in hot environment. [Chinese Journal of Animal Nutrition, 2006,18（3） ：154-159 ]