不同蛋白质水平的日粮对奶牛生产性能的影响

不同蛋白质水平的日粮对奶牛生产性能的影响(14 页)Good is good, but better carries it.精益求精，善益求善。毕 业 论 文 （ 2025 届 ）题 目： 不同蛋白质水平的日粮对奶牛生产性能的影响学 院 农 学 院 专 业 动物科学 年 级 2025 级 学生学号 12025241517 学生姓名 眭 丹 指导老师 张 巧 娥 2011 年 5 月 10 日不同蛋白质水平的日粮对奶牛生产性能的影响摘 要本试验选用30头体况、年龄、胎次相近、健康的荷斯坦奶牛,采纳完全随机单位组试验设计，随机分为三组, 每组10头。饲喂三种不同蛋白质水平的日粮, (试验I、II、III组CP分别为 16.7%、 18.6%、 20.6%)，来讨论对奶牛生产性能的影响。试验结果表明：随着日粮蛋白质水平的增加，奶牛的干物质采食量和产奶量增加，乳脂率和乳蛋白率反而降低，且三组间差异显著（P<0.05）；乳糖随日粮蛋白水平的增加而升高（P<0.05），对乳中尿素氮无明显影响（P>0.05）。关键词: 蛋白质水平 产奶量 乳成分 荷斯坦奶牛Effects of different dietary protein levels on performance ofdairy cows in dietAbstract 30 similar body condition, age, parity, healthy Holstein cows were randomly divided into 3 groups of 10 head in this experiment adopting completely random design. 3 different protein levels in diet(CP 16.7%, 18.6%, 20.6% in experiment I, II III group repectively) were fed to study effects on performance of dairy cows.The results were shown that dry matter intake and milk yields were increased, fat contents and protein contents were decreased cows with dietary protein level was increased, which were significant different in the three groups (P<0.05). Lactose increased significantly (P <0.05), urea nitrogen in milk had no effect (P> 0.05) with increasing dietary protein level.Key words: Different protein levels Milk yields Milk composition Holstein cows 目 录1 引言..............................................................................................................................................11.1 蛋白质主要功...