博落回提取物替代抗生素对肉鸡生长性能、盲肠微生物及盲肠紧密连接的影响

Effects of Macleaya cordata extracts instead of antibiotics on growth performance, caecum microbes and tight junction gene expression of yellow-feathered broilers

摘要:

[目的] 本研究旨在探讨博落回提取物（Macleaya cordata extract，MCE）替代促生长抗生素（Antibiotic growth promoters，AGPs）对黄羽肉鸡生长性能、盲肠微生物及紧密连接mRNA表达的影响。[方法] 试验选取体重相近、体型均匀、健康状况良好的1日龄温氏新黄鸡二号公鸡300只，随机分为5组，每组6个重复，每个重复10羽。分别饲喂基础日粮（NC）、抗生素日粮（ANT，基础日粮添加50 mg/kg那西肽和50 mg/kg金霉素）和试验日粮（基础日粮中添加200、400、800 mg/kg MCE），试验期60 d。[结果] 日粮添加400 mg/kg MCE替代AGPs显著降低了料肉比（P<0.05），并显著增加了盲肠长度（P<0.05）。日粮添加MCE显著提高了肉鸡盲肠食糜中Firmicutes细菌数量和Clostridium cluster XIVa数量（P<0.05）；MCE替代AGPs显著降低了盲肠Escherichia coli数量（P<0.05）。400 mg/kg和800 mg/kg MCE替代日粮中AGPs显著增加了肉鸡盲肠食糜中总短链脂肪酸、乙酸和丁酸含量（P<0.05）；400 mg/kg MCE替代AGPs显著提高了盲肠中支链脂肪酸异丁酸和异戊酸的浓度（P<0.05）。日粮添加MCE显著上调了肉鸡盲肠Claudin-1、JAM2、ZO-1的mRNA表达量（P<0.05），并降低了黏蛋白MUC2、MUC5ac和MUC13的表达量（P<0.05）。[结论] MCE替代AGPs可通过提高盲肠有益菌数量和短链脂肪酸浓度，促进肠道发育，提升肠道屏障功能等途径，改善黄羽肉鸡生长性能，本研究中其最适添加量为400 mg/kg。

关键词:博落回提取物;黄羽肉鸡;盲肠微生物;紧密连接

Abstract:

[Objective] The aim of this study was to evaluate the effects of Macleaya cordata extracts (MCE) instead of antibiotics on growth performance, caecum microbes, short chain fatty acids (SCFAs) and tight junction mRNA expression in yellow-feathered broilers.[Methods] A total of 300 one-day-old Wenshi new yellow broilers No. 2 with similar body weight were randomly allotted to 5 groups, with 6 replicates and 10 broilers per replicate. Broilers in control group were fed a basal diet (NC) and broilers in antibiotic group (ANT), fed a basal diet with 50 mg/kg Nosiheptide and 50 mg/kg chlortetracycline, while those in the treatment groups were fed a basal diet supplemented with 200, 400 and 800 mg/kg MCE. The experiment was lasted for 60 days.[Results] The addition of 400 mg/kg MCE to replace antibiotic growth promoter in yellow-feathered broilers diet significantly reduced (P<0.05) the feed conversion ratio, and significantly increased (P<0.05) the length of the cecum. Dietary supplementation with MCE significantly increased (P<0.05) the cecal Firmicutes and Clostridium cluster XIVa counts and significantly decreased (P<0.05) the Escherichia coli counts. Supplemented with 400 and 800 mg/kg MCE to replace AGPs significantly increased (P<0.05) the cecal total short-chain fatty acids, acetic acid and butyric acid, and 400 mg/kg MCE significantly increased the branched-chain fatty acids, including isobutyrate and isovalerate (P<0.05). Supplementation with MCE in no AGPs diet significantly increased the expression of Claudin-1, JAM2 and ZO-1 (P<0.05). And MCE instead of AGPs significantly increased the expression of JAM2 (P<0.05). However, the addition of MCE to the diet significantly reduced the gene expression of MUC2, MUC5ac and MUC13 (P<0.05).[Conclusion] The MCE replace dietary AGPs of yellow-feathered broilers improves the growth performance promotes caecum growth, and help to establish a stable and healthy intestinal barrier which through increasing the number of beneficial bacteria, SCFAs concentration and regulate the expression of tight junction proteins expression. The optimal addition amount of MCE under this experiment is 400 mg/kg.

Key words:Macleaya cordata extracts;yellow-feathered broilers;caecum microbes;tight junction