不同水平DDGS对奶牛乳产量和乳成分的影响

选择18头荷斯坦奶牛，设置3个处理，每个处理6个重复，每个重复1头奶牛。分别在饲料中添加15％（Ⅰ组）、25％（Ⅱ组）和35％（Ⅲ组）的DDGS，研究不同添加水平的DDGS对奶牛产奶量和乳成分的影响。试验结果表明：①试验Ⅱ组平均产奶量为10．99kg·d^-1，比Ⅰ组提高了4．67％，差异不显著（P〉0．05）；比Ⅲ组提高了9．03％，差异显著（P〈0．05）；②不同处理间的乳脂率差异不显著（P〉0．05）；对于乳糖和乳蛋白含量，Ⅱ组与Ⅰ组和Ⅲ组差异不显著（P〉0．05）；对于乳干物质，试验第15天时，Ⅱ组比Ⅰ组提高了4．39％（P〈0．05），比Ⅲ组提高了1．19％（P〉0．05）。根据上述生产性能指标综合评定，建议奶牛配合饲料中DDGS适宜添加量为25％。

Effects of Different Levels of DDGS on Milk Yield and Milk Composition of Dairy Cows

Eighteen Holstein cows were used to study the effects of different levels of DDGS on milk production and milk composition. It included three treatments： adding 15%, 25%, 35% of DDGS （group Ⅰ-Ⅲ） in dairy cow feed, each treatment had six duplications and each duplication contained one dairy cows.The results were as follows： ①Milk production was 10.99 kg·d ^-1 for group Ⅱ, it increased 4.67% compared with group Ⅰ , there was no significant differences（P〉0.05）; but compared with group m it significantly inereased 9.03%（P〈0.05）; ②There were no significantly differences in fat percentage between three experimental groups; group Ⅱ didn＇t have significantly differences compared with group I in lactose and milk protein contents（P〉0.05）; but for milksolids, group Ⅱ increased 4.39% and 1.19% compared with group Ⅰ（P〈0.05） and groupⅢ （P〉0.05）, on the 15th experimental day. According to above synthesis evaluation of its performance index, the optimization level of DDGS was 25% in cow compound feed.