不同精粗比日粮对奶牛产奶性能的影响

Effects of different concentrate-to-roughage ratios of diet on the milk production performance of dairy cows

[目的]为探讨合理的日粮精粗比,提高奶牛的产奶性能。[方法]试验选用48头中国荷斯坦奶牛,年龄3~5岁,随机分为4组,每组12头,分别饲喂精粗比为50∶50、60∶40、65∶35和70∶30的饲粮,编号为A、B、C、D组,预试验7 d,正式试验周期30 d,检测各组试验奶牛产奶性能及牛乳品质。[结果]随着精料比例的提高,荷斯坦奶牛的产奶性能和牛奶品质均明显提高;高精粗比饲粮组(C、D组)的奶牛饲喂30 d后,日产奶量分别达到21.51、22.65 kg,而料肉比显著降低;牛乳中乳蛋白率和乳总固体物显著升高,C、D组分别是3.17%、11.87%及3.19%、11.97%,两组的牛奶品质比较接近。[结论]在一定范围内,提高日粮中精料的添加比例可有效提高奶牛的产奶性能,改善牛乳品质,综合成本因素,且在本试验条件下,饲喂精粗比为65∶35的日粮效果最佳。

[Objectives]A reasonable concentrate-roughage ratio of diet was studied to improve the milk production performance of dairy cows.[Methods]48 Holstein cows from China aged 3-5 years were randomly divided into 4 groups,with 12 cows in each group.They were fed with concentrate-to-roughage ratios of diet as 50∶50,60∶40,65∶35,and 70∶30,and numbered as the group A,group B,group C,and group D.The preliminary experiment lasted for 7 days,and the formal experiment period was 30 days.The milk production performance and milk quality of dairy cows in each group were investigated.[Results]The milk performance and milk quality of dairy cows were significantly improved with the increase of the concentrate-to-roughage ratios of diet.After feeding cows in the group with high concentrate-to-roughage ratios of diet(group C and group D)for 30 days,their daily milk production reached 21.51 and 22.65 kg,while the conversion rate of feed decreased significantly.The rate of milk protein and total milk solid in group C and group D increased significantly,with 3.17%and 11.87%,and 3.19%and 11.97%,respectively.The milk quality of the two groups is relatively similar.[Conclusions]Increasing the concentrate-to-roughage ratios of diet within a certain range can effectively increase the milk production performance of dairy cows,improve the milk quality.Feeding a diet with a concentrate-to-roughage ratio of 65∶35 has the best effect taking into account cost factors and under the conditions of current experiment.