麦秸型粗饲料日粮不同精粗比对瘤胃内环境和血液指标的影响

Effects of different ratios of concentrate to roughage of wheat straw-based diet on rumen environment and blood parameters

为了研究不同精粗比的麦秸型粗饲料日粮对奶牛瘤胃pH值和挥发性脂肪酸(乙酸、丙酸、丁酸)浓度以及血清矿物质含量和生化指标的影响,选用3头体重为(450±5)kg的健康空怀荷斯坦奶牛,采用3×3拉丁方试验设计,分别以精粗比为40∶60、60∶40和80∶20的麦秸型日粮饲喂奶牛。结果显示,麦秸型日粮精粗比在60∶40时瘤胃pH值较高,80∶20时pH值显著下降(P<0.05);随日粮精粗比的增加,瘤胃乙酸/丙酸比值下降,丙酸、丁酸含量显著增加;随日粮精粗比的增加,血清钾含量升高(P<0.05),其他矿物质含量无显著变化(P>0.05);血清葡萄糖含量显著增加(P<0.05),血清总蛋白质、白蛋白、尿素氮含量无显著变化(P>0.05)。日粮精粗比能显著改变瘤胃pH值、挥发性脂肪酸含量、血清钾含量和血清葡萄糖含量。

To evaluate the effects of different ratios of concentrate to roughage of wheat straw-based diet on rumen pH value, volatile fatty acids （acetic acid, propionic acid, butyric acid） concentrations, and serum mineral and biochemical indicators, three healthy nonpregnant Holstein cows with body weight （450 ± 5 ） kg were selected and the experiment was designed with 3 × 3 Latin square method. The cows were fed with diet in different ratios of concentrate to roughage （40 ： 60, 60 ： 40, 80 ： 20） respectively. The results showed that the rumen pH was higher when concentrate-to-roughage ratio was 60 ： 40, but decreased significantly when concentrate-to-roughage ratio was 80 ： 20. With the increase of the ratio of concentrate to roughage, the ratio of acetic acid to propionic acid in rumen decreased, and the contents of propionie acid and butyric acid increased significantly. With the increase of the ratio of concentrate to roughage, serum K＋ content increased （P〈0. 05 ）, but no significant changes of other mineral contents were observed （P〉0. 05 ） ; the serum glucose content increased significantly （P〈 0. 05 ）, but the contents of serum total protein, serum albumin and serum urea nitrogen didn＇ t change significantly （P〉0. 05 ）. It was concluded that concentrate-to-roughage ratio could significantly change the rumen pH value, volatile fatty acid proportion, serum K＋content and serum glucose content.