鸡源复合益生菌对肉仔鸡免疫球蛋白及Toll样受体通路的影响

Effects of chicken-derived compound probiotics on immunoglobulin and Toll-like receptor pathway of broilers

【目的】探究益生菌对肉仔鸡血清免疫球蛋白与肠道Toll样受体通路的影响。【方法】选择90只1日龄白羽肉杂鸡,随机分为3组,即对照组、益生菌低剂量组和益生菌高剂量组。其中对照组饲喂基础日粮,益生菌低剂量组在每千克基础日粮中添加复合益生菌10^9 cfu,益生菌高剂量组在每千克基础日粮中添加复合益生菌2×10^9 cfu。第21天,每组随机选取10只鸡放血致死,并立即采集样本,进行ELISA、免疫组化、qPCR及Western blot检测。【结果】在第21天,益生菌低剂量组和益生菌高剂量组鸡的料肉比分别比对照组降低9%和12%(P<0.05),血清IgG含量分别升高28%和40%(P<0.01),血清IgM含量分别升高44%和58%(P<0.01)。益生菌低剂量组TLR4蛋白表达和mRNA相对表达量比对照组分别升高33%和28%,AP-1蛋白表达和mRNA相对表达量分别比对照组升高106%和67%(P<0.01);益生菌高剂量组TLR4蛋白表达及mRNA相对表达量比对照组分别升高106%和69%,AP-1蛋白表达及mRNA相对表达量比对照组分别升高163%和98%(P<0.01)。【结论】饲喂益生菌可降低肉仔鸡料肉比,提高血清中IgG、IgM的含量,并且通过调节Toll样受体通路蛋白表达可以提高机体免疫力。

【Objective】To investigate the effects of probiotics on serum immunoglobulin and intestinal Tolllike receptor pathway in broilers.【Method】Ninety one-day-old white feather chicks were randomly divided into three groups including control group, low-dose probiotic group and high-dose probiotic group. The chicks in control group were fed basal diet, 109 cfu probiotics per kg basal diet were added in the low-dose probiotic group, and 2×10^9 cfu probiotics per kg basal diet were added in the high-dose probiotic group. On the 21 st day,ten chicks in each group were sacrificed by bloodletting, and the samples were collected immediately for ELISA,immunohistochemistry, qPCR and Western blot.【Result】Compared with the control group on the 21 st day,the feed conversion ratios of low-and high-dose probiotic groups decreased by 9% and 12%(P<0.05), the IgG levels in serum increased by 28% and 40%(P<0.01), and the IgM levels in serum increased by 44% and 58%(P<0.01) respectively. The protein and mRNA expression of TLR4 increased by 33% and 28% respectively in low-dose probiotic group(P<0.01), and the protein and mRNA expression of AP-1 increased by 106% and 67%respectively in low-dose probiotic group(P<0.01). The protein and mRNA expression of TLR4 increased by106% and 69% respectively in high-dose probiotic group(P<0.01), and the protein and mRNA expression of AP-1 increased by 163% and 98% respectively in high-dose probiotic group(P<0.01).【Conclusion】Feeding probiotics can reduce the feed conversion ratio in broilers, increase the levels of IgG and IgM in serum, and enhance the immunity by regulating the expression of Toll-like receptor pathway proteins.