耐久肠球菌D22及其发酵液对肉鸡生长性能、血清生化指标、肠道形态和盲肠菌群的影响

Effects of Enterococcus durans D22 and Its Fermentation Broth on Growth Performance,Serum Biochemical Indexes,Intestinal Morphology and Cecal Flora in Broilers

试验旨在研究耐久肠球菌D22及其发酵液对肉鸡生长性能、血清生化指标、肠道形态以及盲肠微生物菌群的影响。选取1日龄体重相近、健康状态良好的罗斯308肉公鸡150只,随机分为3组,每组5个重复,每个重复10只鸡。对照组饲喂基础饲粮,抗生素组在基础饲粮中添加40 mg/kg金霉素,试验组在基础饲粮中添加2×10^(8)CFU/kg耐久肠球菌和6%耐久肠球菌D22浓缩发酵液。试验期42 d,分为1~21日龄和22~42日龄2个阶段。试验结果表明:(1)1~21日龄,与对照组相比,D22组肉鸡平均日增重和平均日采食量显著提高(P<0.05),料重比显著降低(P<0.05)。(2)与对照组和抗生素组相比,D22组肉鸡血清白蛋白和免疫球蛋白A含量显著提高(P<0.05);血清总蛋白、免疫球蛋白G含量与对照组相比显著升高(P<0.05)。(3)与对照组和抗生素组相比,D22组肉鸡十二指肠绒毛高度显著升高(P<0.05);十二指肠和空肠的隐窝深度显著降低且绒毛高/隐窝深显著提高(P<0.05)。(4)在门水平,与对照组相比,抗生素组和D22组肉鸡盲肠微生物中变形菌门和放线菌门相对丰度显著降低(P<0.05)。在属水平,与对照组相比,抗生素组和D22组肉鸡盲肠菌群中粪杆菌属相对丰度显著升高,寡养单胞菌属相对丰度显著降低(P<0.05)。综上所述,饲粮添加2×10^(8)CFU/kg耐久肠球菌及6%耐久肠球菌D22浓缩发酵液,可以显著提高1~42日龄罗斯肉鸡的生长性能和降低盲肠有害菌群;并且在促进免疫功能以及小肠发育方面,其效果优于抗生素。

The purpose of this experiment was to study the effects of Enterococcus durans D22 and its fermentation broth on the growth performance,serum biochemical indexes,intestinal morphology and cecal microbial flora of broilers.One hundred and fifty Ross 308 broiler roosters with similar weight and good health at 1 day of age were randomly divided into 3 groups of 5 replicates,with 10 broilers in each replicate.The basis diet was fed in control group,40 mg/kg chlortetracycline was added in antibiotic group,and 2×10^(8)CFU/kg Enterococcus durans and 6%concentrated fermentation of Enterococcus durans D22 were added in D22 group.The experimental period was 42 days which was divided into two stages:1-21 days and 22-42 days.The results showed:①from 1 to 21 days,compared with the control group,the average daily gain and average daily feed intake of broilers in the D22 group were significantly higher(P<0.05)and the feed-to-weight ratio was significantly lower(P<0.05).②The serum albumin and immunoglobulin A contents of broilers in the D22 group were significantly increased(P<0.05)compared with the control group and the antibiotic group;serum total protein,immunoglobulin G content was significantly higher than that in the control group(P<0.05).③Compared with the control group and the antibiotic group,the duodenal villus height in the D22 group was significantly increased(P<0.05);the crypt depth of the duodenum and jejunum was significantly decreased and the villus was high/crypt depth was significantly increased(P<0.05).④At the phylum level,compared with the control group,the relative abundances of Proteobacteria and Actinobacteria in the caecal microorganisms of broilers in the antibiotic group and D22 group were significantly decreased(P<0.05).At the genus level,the relative abundance of Faecalibacterium in the caecal flora of broilers in the antibiotic group and D22 group was significantly increased,and the relative abundance of Stenotrophomonas was significantly decreased compared with the control group(P<0.05).To sum up,dietary supplementation of 2×10^(8)CFU/kg Enterococcus durans and 6%Enterococcus durans D22 concentrated fermentation broth can significantly improve the growth performance of 1-42-day-old Ross broilers and reduce cecal harmful flora;And it is more effective than antibiotics in promoting immune function and small intestine development.