本试验旨在研究复合微生物制剂对育肥牛生长性能、养分表观消化率、瘤胃酶活性和糖脂代谢的影响。选择12月龄左右、体重[（500±25）kg]相近的荷斯坦公牛20头，按体重随机分为2组，对照组不添加复合微生物制剂，试验组每头牛添加80 g/d复合微生物制剂（酿酒酵母、枯草芽孢杆菌、地衣芽孢杆菌，三者组成比例为7：2：1）。试验预试期7 d，正试期55 d。每天准确记录采食量，并于试验开始和结束时清晨空腹称重，连续收集7 d粪便用以测定养分表观消化率，试验中期抽取瘤胃液用以测定酶活性，试验结束时空腹采集静脉血进行糖脂代谢检测。结果表明：与对照组相比，1）试验组干物质采食量与平均日增重分别提高2.74%和28.95%（P<0.05）；2）试验组干物质表观消化率无显著差异（P>0.05），但是粗蛋白质表观消化率提高1.56%（P<0.05），中性洗涤纤维表观消化率提高1.93%（P<0.05）；3）试验组瘤胃液中蛋白酶活性提高8.87%（P<0.01），淀粉酶活性提高10.27%（P<0.05），但是脂肪酶活性并未发生显著改变（P>0.05），果胶酶活性提高18.63%（P<0.01），木聚糖酶和滤纸酶活性未见显著变化（P>0.05）；4）试验组血清中葡萄糖含量升高11.67%（P<0.01），胆固醇和甘油三酯含量分别升高22.91%和12.84%（P<0.01）。由此可见，复合微生物制剂对于育肥牛的干物质采食量和增重效果都有促进作用，能够在一定程度上改善料重比，并且复合微生物制剂能够提高部分瘤胃消化酶活性，改善营养物质的消化吸收。

This experiment was conducted to study the effects of compound microbial preparation on the growth performance, nutrient apparent digestibilities, rumen enzyme activities and glycolipid metabolism of fattening cattle. Twenty 12-month-old Holstein bulls with the similar weight of (500±25) kg were randomly divided into two groups, which was experimental group and control group. The compound microbial preparation (Saccharomyces cerevisiae, Bacillus subtilis, Bacillus licheniformis, and the ratio of the three was 7:2:1) amount of each cattle in the experimental group was 80 g/d, and no compound microbial preparation were added to the control group. Preliminary period lasted for 7 d, and test period lasted for 55 d. Feed intake was accurately recorded every day and weighed in the morning at the beginning and the end of the experiment, separately. Feces were continuously collected for 7 days to determine nutrient apparent digestibilities. Rumen juice was extracted in the middle of the experiment to determine enzyme activities, and venous blood was collected at the end of the experiment for glycolipid metabolism detection. The results showed as follows:compare with control groups, 1) the dry matter intake and average daily weight gain in the experimental group increased by 2.74%(P<0.05)and 28.95%(P<0.05), respectively; 2) the apparent digestibility of dry matter in experimental group had no significant change (P>0.05). However, the apparent digestibilities of crude protein and neutral detergent fiber increased by 1.56% and 1.93%(P<0.05),respectively; 3)the activities of protease and amylase of rumen juice in the experimental group increased by 8.87% (P<0.01)and 10.27%(P<0.05),respectively. However, lipase activity did not found apparent change (P>0.05). The activity of pectinase in the experimental group increased by 18.63% (P<0.01), but the activities of xylanase and filter paper enzyme were not significantly different from that of control group (P>0.05); 4)the serum glucose content in the experimental group increased by 11.67% (P<0.01), and cholesterol and triglyceride contents increased by 22.91% and 12.84%(P<0.01), respectively. In conclusion, the compound microbial preparation can promote the dry matter intake and weight gain of fattening cattle, and improve the feed-to-weight ratio to a certain extent as well. In addition, the compound microbial preparation can improve the activities of rumen digestive enzymes and the digestion and absorption of nutrients as well.