含抗菌肽酵母工程菌对肉仔鸡肠道菌群和免疫功能的影响

目的 研究含抗菌肽（Cec Md、3cs、3js）酵母工程菌对肉仔鸡肠道菌群和免疫功能的影响。方法 采用随机试验设计的方法，选用1日龄健康爱拔益加肉仔鸡400只，随机分成5组，每组设4个重复，每个重复20只鸡（雌雄各半）。空白对照组常规饮水，抗生素组在饮水中添加50 mg/L的泰乐菌素，抗菌肽实验组分别在饮水中添加8 mg/L含Cec Md、3cs和3js酵母工程菌，实验期42 d。结果 （1）Cec Md组的第1、4和5周及3cs组第3、5周的大肠埃希菌数量显著低于空白对照组（P<0.05）；Cec Md组和3cs组的第2至第6周及3js组的第2至第4周沙门菌数量显著低于空白对照组（P<0.05）；Cec Md组的第4至第6周及3cs组和3js组的第5周的乳杆菌数量显著高于空白对照组（P<0.05）；Cec Md组的第2、3、5周和6周及3cs组第5、6周及3js组的第3至第6周的双歧杆菌数量显著高于空白对照组（P<0.05）。（2）Cec Md组的第3、5周及3cs和3js组的第6周的IgA含量显著高于空白对照组（P<0.05）；Cec Md组和3js组的第3周的IgG含量显著高于空白对照组（P<0.05）。3js组的第1周的IgM含量显著高于空白对照组（P<0.05），Cec Md组第4、5周的IgE含量显著高于空白对照组（P<0.05）。结论 含抗菌肽Cec Md、3cs和3js酵母工程菌可以抑制肉仔鸡肠道有害菌群的生长，促进其有益菌群的增殖，且可以改善肉仔鸡的免疫功能。

Effects of yeast engineering bacteria containing antimicrobial peptides Cec Md onintestinal flora and immune function of broilers

Objective To observe the effects of antimicrobial peptides (Cec Md, 3cs, 3js) on the intestinal flora and immune function of broilers. Methods 400 one-day-old Arbor Acres (AA) broilers were randomly divided into 5 treatment groups with 4 replicates per group and 20 broilers per replicate (male:female = 1:1). The broilers in blank control group were given pure drinking water; the antibiotic group was given 50 mg/L tylosin (added in drinking water), while the 3 antimicrobial peptide groups were given 8 mg/L Cec Md, 3cs or 3js respectively (added in drinking water). The trial period was 42 days. Results (1) Compared to the blank control group, the amounts of Escherichia in the Cec Md group at wk1, wk4 and wk5 as well as in the 3cs group at wk3 and wk5 were significantly lower (P<0.05); The amounts of Salmonella in Cec Md group and 3cs group at wks 2 to 6 as well as in 3js group at wks 2 to 4 were significantly lower (P<0.05); The amounts of Lactobacilli in Cec Md group at wks 4 to 6 as well as in 3cs group and 3js group at wk5 were significantly higher (P<0.05); The amounts of Bifidobacteria in Cec Md group at wk2, wk3, wk5 and wk6, in 3cs group at wk5 and wk6, as well as in 3js group at wks 3 to 6 were significantly higher (P<0.05). (2) Compared with the blank control group, the serum IgA levels in Cec Md group at wk3 and wk5, as well as in 3cs group and 3js group at wk6 were significantly higher (P<0.05); The IgG levels in Cec Md group and 3js group at wk3 increased significantly (P<0.05); The IgM level in 3js group at wk1 was significantly higher (P<0.05); The IgE levels in Cec Md group at wk4 and wk5 were significantly higher (P<0.05). Conclusion The yeast engineering bacteria containing antimicrobial peptides Cec Md, 3cs and 3js can inhibit the growth of harmful intestinal flora in broilers, promote the growth of beneficial bacteria, and improve the immune function of broilers.