[目的] 研究奶牛日粮中添加菌酶制剂对其血液生化指标及免疫指标的影响。[方法] 选某规模化奶牛场200 头身体健康,胎次、年龄相近的泌乳奶牛为研究对象,用随机数字表法分4 组（n=50）,分别为对照组（基础日粮）、菌酶制剂1组（基础日粮+0.1%菌酶制剂）、菌酶制剂2组（基础日粮+0.2%菌酶制剂）和菌酶制剂3组（基础日粮+0.3%菌酶制剂）。每组设置5 个重复,每个重复10 头。预试期7 d,正试期42 d。统计分析各组泌乳奶牛的血液生化和免疫指标。[结果] 菌酶制剂1组、2组和3组ALT、TBIL、CK、ALB、BUN、Na、P、Ca等血液生化指标优于对照组（P<0.05）。菌酶制剂2组血液生化指标最理想。对照组、菌酶制剂1组、2组和3组IgM、IgG、TNF-α无显著差异（P>0.05）。菌酶制剂2组IgA高于1组、3组和对照组（P<0.05）,其中菌酶制剂1组和3组无显著差异（P>0.05）。菌酶制剂1组、2组和3组IL-2高于对照组（P<0.05）,菌酶制剂1组、2组和3组无显著差异（P>0.05）。[结论] 菌酶制剂可改善泌乳奶牛血液生化指标,增强机体免疫能力,以0.2%添加量最适宜。

[Objective] To study the effects of adding bacterial enzyme preparations to dairy cow diet on blood biochemical and immune indexes.[Method] A total of 200 healthy lactating cows with similar age and parity in a large-scale dairy farm were selected as the research objects and divided into 4 groups（n=50） by random number table method.They were divided into control group（basic diet）,bacterial enzyme preparation group 1（basic diet+0.1% bacterial enzyme preparation） and bacterial enzyme preparation group 2（basic diet+0.2% bacterial enzyme preparation） and bacterial enzyme preparation group 3（basic diet+0.3% bacterial enzyme preparation ）. Each group was set with 5 replicates and 10 lactating cows per replicate.The pre-test period lasted for 7 days and the test period lasted for 42 days.The blood biochemical and immune indexes of lactating cows in each group were analyzed statistically.[Result] ALT,TBIL,CK,ALB,BUN,Na,P,Ca and other blood biochemical indexes of lactating cows in bacterial enzyme preparation group 1,group 2 and group 3 were better than those in control group（P<0.05）. The blood biochemical indexes of bacterial enzyme preparation group 2 were the best.There was no significant difference in IgM,IgG and TNF-α in control group,bacterial enzyme preparation group 1,group 2 and group 3（P> 0.05）. IgA in bacterial enzyme preparation group 2 was higher than that group 1,group 3 and control group（P<0.05）,and there was no significant difference between bacterial enzyme preparation group 1 and group 3（P>0.05）.IL-2 in bacterial enzyme preparation group 1,group 2 and group 3 were higher than that in control group（P<0.05）,and there was no significant difference in IL-2 in group 1,group 2 and group 3（P>0.05）.[Conclusion] Bacterial enzyme preparation could improve the blood biochemical indexes of lactating cows and enhance the immune capacity of the body,and 0.2% was the most suitable addition.