过瘤胃保护烟酸对奶牛生产性能的影响及经济效益分析

本研究采用对比饲养试验,研究日粮中添加过瘤胃保护烟酸产品对荷斯坦牛泌乳初期和高峰期产奶量和乳成分的影响,并对经济效益进行了分析。试验选用54头体重、胎次、泌乳月、上一胎产奶量相近的荷斯坦牛为试验动物,按照配对原则随机分成三组:试验Ⅰ组、试验Ⅱ组和对照组,每组18头。对照组饲喂牛场常规TMR,试验Ⅰ组在常规TMR基础上每日每头添加本实验室研发的过瘤胃保护烟酸产品20g,试验Ⅱ组添加等量普通烟酸,进行95d的饲养试验。结果表明:(1)在产犊后6～100d高产荷斯坦牛日粮中添加过瘤胃保护烟酸可明显提高产奶量(50.12 V 45.44kg/头日,P<0.05);但乳蛋白含量明显降低(3.09%V 3.21%,P<0.05),对乳脂率(3.56%V 3.63%,P>0.05)和乳糖含量(5.05%V 4.99%,P>0.05)的影响很小。(2)添加等量的普通烟酸对产奶量的提高效果不明显(46.29 V 45.44kg/头日,P>0.05);对乳脂率(3.48%V 3.63%,P>0.05)、乳蛋白(3.14%V 3.27%,P>0.05)和乳糖含量(5.00%V 4.99%,P>0.05)的影响均不显著。(3)添加过瘤胃保护烟酸可获得较高的经济效益增收12.35元/(头.d)];添加普通烟酸后效益则略下降-1.74元/(头.d)]。上述结果提示,在高产奶牛泌乳初期和高峰期日粮中应添加过瘤胃保护烟酸,添加普通烟酸无效。

Effect of Supplementing Rumen Protected Niacin on Milk Performance of Dairy Cow and Economic Benefits Analysis

In this study, a comparison of feeding trials were developed in this laboratory to study the effects of added RPN（rumen-protected niacin） products on early lactation and peak lactation milk production and milk composition, and economic benefits. The selection of 54 test weight, parity, lactation month, a similar amount of the previous lactation milk yield of Holstein cows as experimental animals, in accordance with the matching principle were randomly divided into three groups： the experimental group I, the experimental group II and the control group （n =18）. The control group was fed cattle conventional TMR diet; in the experimental group I, on the basis of the conventional TMR diets added this RPN products 20g/（head.d）; the experimental control group II, added an equal amount of ordinary nicotinic acid, the 95d of feeding trial. The results showed that： （1）100 days after calving yielding Holstein dairy cows add RPN can significantly increase milk yield 50.12 V 45.44kg/（head.d）, P 〈0.05）; can significantly reduce the milk protein content （3.09% V 3.21%, P 〈0.05） on milk fat percentage （3.56 % V 3.63%, P〉 0.05） and lactose content （5.05% V 4.99%, P〉 0.05） has little effect. （2） add the improvement of the ordinary and rumen-protected niacin the same amount of niacin on milk yield little effect 46.29 V 45.44kg/（head.d）, P〉 0.05]; milk fat percentage （3.48% V 3.63%, P〉 0.05）, milk protein （3.14% V 3.27%, P〉 0.05） and lactose content （5.00% V 4.99%, P〉 0.05） has little effect. （3） added RPN can obtain higher economic returns （￥12.35/head.d）; to add contrast to ordinary niacin same amount of rumen-protected （￥-1.74/head.d）. These results suggest that high producing dairy cows in early lactation diet should be added rumen-protected niacin, adding ordinary nicotinic was acid invalid.