摘要
文章旨在探讨不同粗蛋白质水平浓缩料对泌乳早期奶牛生产性能、氮代谢及瘤胃发酵性能的影响。试验将泌乳早期、生产性能一致的60头奶牛随机分为3组,每组5个重复,每个重复4头。各组奶牛分别饲喂粗蛋白质水平为10%、15%和20%的浓缩饲料,同时在整个8周的饲养试验期间自由采食水稻秸秆。结果:20%蛋白质组奶牛的干物质和水稻秸秆摄入量及4%脂肪校正乳和乳蛋白质产量均显著高于10%蛋白质组(P<0.05),同时20%蛋白质奶牛泌乳量、乳脂肪产量也显著高于10%和15%蛋白质组(P<0.05)。20%蛋白质组奶牛乳脂肪含量显著高于15%蛋白质组(P<0.05)。随着浓缩料蛋白质水平的升高,乳尿素氮含量表现为显著升高(P<0.05)。随着浓缩料粗蛋白质水平的升高,氮摄入量、尿氮和总氮排泄量表现为显著升高(P<0.05)。20%蛋白质组奶牛乳氮含量、粪氮排泄量和氮平衡均显著高于10%蛋白质组(P<0.05)。与10%蛋白质组相比,15%和20%奶牛组氮利用效率分别显著降低25.92%和30.76%(P<0.05)。随着浓缩料蛋白质水平的升高,瘤胃氨氮浓度表现为显著升高(P<0.05)。与10%蛋白质组相比,15%和20%蛋白质组奶牛瘤胃丁酸浓度分别显著提高28.44%和26.86%(P<0.05)。结论:饲喂粗蛋白质水平为20%的浓缩料提高了泌乳早期奶牛的采食量、泌乳量及乳脂肪和乳蛋白产量,但增加了氮排泄量,对微生物氮的合成无负面影响。
The experiment was conducted to investigate the effects of different crude protein concentrate levels on performance,nitrogen metabolism and rumen fermentation performance of dairy cows in early lactation.Sixty cows with consistent performance in early lactation were randomly divided into 3 groups with 5 replicates per group and 4 cows per replicate.Dairy cows in each group were fed concentrated diets with crude protein levels of 10%,15%and 20%,respectively,and at the same time,they were free to eat rice straw during the whole 8-week feeding experiment.Results:Dry matter and rice straw intake,4%fat corrected milk and milk protein yield of 20%protein group were significantly higher than those of 10%protein group(P<0.05),meanwhile,milk yield and milk fat yield of 20%protein group were also significantly higher than those of 10%and 15%protein groups(P<0.05).Milk fat content in 20%protein group was significantly higher than that in 15%protein group(P<0.05).The milk urea nitrogen content was significantly increased with the increase of protein level of concentrate(P<0.05).The nitrogen intake,urinary nitrogen and total nitrogen output were significantly increased with the crude protein level of the concentrate increasing(P<0.05).Milk nitrogen content,fecal nitrogen output and nitrogen balance in 20%protein group were significantly higher than those in 10%protein group(P<0.05).Compared with 10%protein group,nitrogen use efficiency in 15%and 20%dairy cow groups was significantly decreased by 25.92%and 30.76%(P<0.05),respectively.The concentration of ammonia nitrogen in the rumen was significantly increased with the increase of protein level in the concentrate(P<0.05).Compared with 10%protein group,rumen butyric acid concentration in 15%and 20%protein groups was significantly increased by 28.44%and 26.86%(P<0.05),respectively.Conclusions:Feeding 20%crude protein concentrate can increase feed intake,milk yield,milk fat and milk protein production in early lactation cows,but increase nitrogen excretion,and has no negative e
作者
郭庆河
赵永旭
GUO Qinghe;ZHAO Yongxu(Xinjiang Agricultural Vocational Technical College,Changji,Xinjiang 831100,China)
出处
《中国饲料》
北大核心
2021年第18期57-60,共4页
China Feed
关键词
粗蛋白质
奶牛
生产性能
氮代谢
瘤胃发酵
crude protein
dairy cow
lactation performance
nitrogen metabolism
rumen fermentation
