牛源复合微生态制剂的应用效果评价

Evaluation of Application Effects of Bovine Compound Microecologic Agent

本试验旨在探究牛源复合微生态制剂对大别山黄牛免疫功能、抗氧化能力及肠道菌群结构的影响,以评价其应用效果。从大别山黄牛的肠道内分离鉴定具有益生潜力的菌株,制备成复合微生态制剂。选取12只体型相近的健康断奶大别山黄牛,随机分为3组,每组4头。对照组(C组)、芽孢杆菌组(B组)、复合微生态制剂组(E组)分别饲喂基础饲粮、添加枯草芽孢杆菌菌粉饲粮和添加牛源复合微生态制剂饲粮。试验期为30 d。于试验第0、15和30天,每组4头犊牛均经颈静脉采血,分离血清,用于细胞因子、免疫与抗氧化指标检测。试验第30天采集牛粪便进行高通量测序,检测菌群丰度与结构变化。结果显示:1)从大别山黄牛体内分离到的菌株包含6株芽孢杆菌与5株乳酸菌,根据耐酸与耐胆盐试验结果,选择枯草芽孢杆菌和乳酸乳球菌制作复合微生态制剂。2)第15、30天时,与C组相比,B组和E组血清免疫球蛋白G(IgG)含量极显著提高(P<0.01),E组血清免疫球蛋白M(IgM)含量极显著高于B组与C组(P<0.01)。3)第30天时,E组血清白细胞介素-2(IL⁃2)、白细胞介素-6(IL⁃6)、γ-干扰素(IFN⁃γ)含量显著高于C组(P<0.05)。4)第30天时,B组与E组血清总抗氧化能力(T⁃AOC)、谷胱甘肽过氧化物酶(GSH⁃Px)与过氧化氢酶(CAT)活性均显著高于C组(P<0.05),E组血清超氧化物歧化酶(SOD)活性极显著高于C组(P<0.01),B组血清SOD活性显著高于C组(P<0.05),B组和E组血清丙二醛(MDA)含量显著低于C组(P<0.05)。5)与C组相比,E组和B组肠道内容物中拟杆菌门所占比例增加,变形菌门所占比例有所降低。综上可知,本试验制备的牛源微生态制剂能够增强大别山黄牛机体的免疫功能及抗氧化能力,改善肠道菌群结构。

The aim of this study was to investigate the effects of bovine compound microecological agent on immune function,antioxidant capacity and intestinal flora structure of Dabie mountain yellow cattle. From the intestine of Dabie mountain cattle,the bacterial strains with probiotic potential were isolated and identified,and the compound microecological agent was prepared. Twelve healthy weaned Dabie mountain yellow cattle with similar body size were randomly divided into 3 groups with 4 cattle in each group. The cattle control group(group C),bacillus group(group B)and compound microecological agent group(group E)were fed with a basal diet,the basal diet supplemented with Bacillus subtilis powder,and the basal diet supplemented with bovine compound microecological agent,respectively. The experiment was conducted for 30 days. On days 0,15 and 30 of the experiment,blood samples were collected from the jugular vein of 4 calves in each group,and the serum was separated for the detection of cytokines,immune and antioxidant indices. On day 30 of the experiment,cattle faces was collected for high-throughput sequencing to detect the abundance and structural changes of bacterial flora. The results showed as follows:1)six strains of bacillus and five strains of lactic acid bacteria were isolated from Dabie mountain yellow cattle,then Bacillus subtilis and Lactococcus lactis were selected to make compound microecological agent according to the results of acid and bile salt tolerance tests. 2)On days 15 and 30,compared with the group C,the serum immunoglobulin G(IgG)content in group B and group E was extremely significantly increased(P<0.01),and the serum immunoglobulin M(IgM)content in group E was extremely significantly higher than that in group C and group B(P<0.01). 3)On day 30,the contents of serum interleukin-2(IL-2),interleukin-6(IL-6)and interferon-γ (IFN-γ)in group E were significantly higher than that in group C(P<0.05). 4)On day 30,compared with group C,the serum total antioxidant capacity(T-AOC)and the activities of glutathione peroxidase(GSH-Px)and catalase(CAT)in group B and group E were significantly increased(P<0.05),the serum superoxide dismutase(SOD)activity in group E was extremely significantly increased(P<0.01),the serum SOD activity in group B was significantly increased(P<0.05),and the malondialdehyde(MDA)content in group B and group E was significantly decreased(P<0.05). 5)Compared with group C,the proportion of Bacteroidetes in group E and group B was increased,while the proportion of Proteobacteria was decreased. In conclusion,the bovine microecological agent prepared in this experiment can enhance the immune function and antioxidant capacity of body,and improve the intestinal flora structure of Dabie mountain yellow cattle.