复合乳酸菌制剂对犊牛生长、肠道菌群与免疫性能的影响

目的]研究复合乳酸菌制剂对犊牛生长、肠道菌群、抗氧化及免疫性能的影响。方法]选取体重相近的30日龄健康荷斯坦犊牛20头，随机分为对照组和试验组，每组10头。对照组与试验组饲喂相同的基础日粮，试验组饮水中添加复合乳酸菌制剂（饮水与复合乳酸菌制剂调配比例为50∶1），对照组不添加，试验期为90 d。计算2组犊牛试验期间平均日增重、腹泻率；分别于试验1、30、60、90 d测定粪便中细菌总数以及乳酸菌和大肠杆菌数量，并测定血液生化、抗氧化与免疫指标。结果]试验组犊牛的平均日增重与对照组相比无显著（P>0.05）差异，腹泻率低于对照组。试验组犊牛粪样中的乳酸菌数量达到1.41×10⁷ CFU/g，显著（P<0.05）高于对照组，而大肠杆菌数量显著（P<0.05）低于对照组。在试验30、90 d时，试验组犊牛血清中的葡萄糖（GLU）含量显著（P<0.05）高于对照组；在试验60、90 d时，试验组犊牛血清中的总蛋白（TP）含量显著（P<0.05）低于对照组。2组犊牛的抗氧化指标均无显著（P>0.05）差异。在试验90 d时，试验组犊牛的血清IgG、IgA含量高于对照组。结论]饮水中添加复合乳酸菌制剂可以改善荷斯坦犊牛肠道菌群结构并降低腹泻率。

Effects of Compound Lactic Acid Bacteria Preparation on Growth Performance,Intestinal Microflora and Immunity of Calves

Objective] This study was conducted to assess the effects of compound lactic acid bacteria preparation on growth performance, intestinal microflora, anti-oxidation capacity and immunity of calves. Method] A total of twenty 30-day-old healthy Holstein calves of similar weights were randomly divided into a control group and an experimental group with 10 individuals for each group. The two groups were fed with the same basal diet. The experimental group received an supplementation of compound lactic acid bacteria preparation through drinking water （the ratio of drinking water to compound lactic acid bacteria preparation was 50∶1）, whereas the control group received no microbial preparation in any forms. The experiment lasted for 90 days. The average daily gain and diarrhea rate of the calves in the two groups during the experiment were calculated. On days 1, 30, 60 and 90 of the experiment, the total number of bacteria as well as the number of lactic acid bacteria and Escherichia coli in the faecal samples, and the blood biochemical, antioxidant and immunological indexes were determined. Result] No significant （P>0.05） difference in average daily gain between the experimental group and the control group was observed. The experimental group had a lower diarrhea rate than control group. The number of lactic acid bacteria in feces of the calves in the experimental group reached 1.41×10⁷ CFU/g, which was significantly （P<0.05） higher than that of the calves in the control group, while the number of Escherichia coli in feces was significantly （P<0.05） lower than the control group. On days 30 and 90 of the experiment, the experimental group had significantly （P<0.05） higher serum content of glucose （GLU） in comparison to the control group. On days 60 and 90 of the experiment, the experimental group had significantly （P<0.05） lower serum content of total protein （TP） than the control group. The anti-oxidant indexes did not differ significantly （P>0.05） between the two groups. Calves in the experiment group had higher serum levels of IgG and IgA on day 90 of the experiment compared with the control group. Conclusion] The addition of compound lactic acid bacteria preparation in drinking water improved the community structure of intestinal microflora and decreased the diarrhea rate of Holstein calves.