凉茶渣替代象草对育肥牛空肠组织形态、屏障功能以及菌群结构的影响

本试验旨在研究凉茶渣替代象草对育肥牛空肠组织形态、屏障功能以及菌群结构的影响。选取120头健康且体重相近的西门塔尔杂交肉牛，随机分为2个组，分别为对照组(饲喂基础饲粮)、试验组(50%凉茶渣替代部分象草)，每组3个重复，每个重复20头。试验期共67 d，包括7 d的预试期，60 d的正试期。在试验期结束后，采集试验牛血液、空肠组织、空肠内容物，通过苏木精-伊红(HE)染色测量空肠绒毛高度、隐窝深度；通过酶联免疫吸附测定(ELISA)试剂盒检测血清中炎症因子、D-乳酸(D-Lac)以及二胺氧化酶(DAO)浓度；通过荧光定量PCR测定空肠紧密连接蛋白基因闭合小环蛋白-1(ZO-1)、闭锁蛋白(Occludin)、闭合蛋白-1(Claudin-1)的mRNA表达水平；利用16S rDNA高通量测序分析空肠菌群结构。结果表明：1)与对照组相比，试验组育肥牛空肠绒毛高度显著增加(P<0.05)，血清中D-Lac浓度显著降低(P<0.05)，空肠紧密连接蛋白ZO-1的mRNA表达水平显著上调(P<0.05)。2)在门水平上，对照组和试验组厚壁菌门(Firmicutes)相对丰度分...

Effects of Herbal Tea Residue on Ileum Morphology,Barrier Function and Flora Structure of Fattening Cattle

This experiment was conducted to study the effects of herbal tea residue on ileum morphology,barrier function and flora structure of fattening cattle. A total of 120 healthy Simmental crossbred beef cattle with similar body weight were randomly divided into two groups:control group(fed a basal diet)and experimental group(50% herbal tea residue replaced part of elephant grass),with 3 replicates in each group and 20 heads in each replicate. The experimental period lasted for 67 days,including 7 days of pre feeding period and 60 days of formal experimental period. At the end of the experimental period,the blood,jejunal tissue and jejunal contents were collected,and the villus height and crypt depth of jejunum were measured by hematoxylin-eosin(HE)staining;the concentrations of inflammatory factors,D-lactic acid(D-Lac)and diamine oxidase(DAO)in serum were measured by enzyme-linked immunosorbent assay(ELISA)kit;the mRNA expression levels of tight junction proteins of zonula occludens-1(ZO-1),Occludin and Claudin-1 in jejunum were determined by fluorescence quantitative PCR;the 16 S rDNA high-throughput sequencing was used to analyze the structure of jejunal flora. The results showed as follows:1)compared with the control group,the jejunal villi height of the experimental group was significantly increased(P<0.05),the serum D-Lac concentration was significantly decreased(P<0.05),and the mRNA expression level of tight junction protein ZO-1 in jejunum was significantly up-regulated(P<0.05). 2)At the phylum level,the Firmicutes relative abundances in the control group and the experimental group were 85.79% and 76.96%,respectively,and the Bacteroidetes relative abundances were 0.54% and 3.11%,respectively. At the genus level,the relative abundances of Romboutsia,Rothia and Blautia showed significant differences between the control group and the experimental group(P<0.05). 3)Pearson correlation analysis displayed that the jejunal villi height showed significant positive correlations with the relative abundances of Blautia,Brevundimonas,Rothia and Tetrasphaera(P<0.05),and the correlation coefficients ranged from 0.46 to 0.57;the serum D-Lac concentration showed significant positive correlations with the relative abundances of Romboutsia and Terrisporobacter(P<0.05),and the correlation coefficients were 0.56 and 0.62,respectively;the mRNA expression level of tight junction protein ZO-1 in jejunum showed a significant negative correlation with the relative abundances of Solobacterium(P<0.05),and correlation coefficient was-0.50. In conclusion,adding 50% herbal tea residue as functional roughage in the diet has positive effects on the jejunal villus height and barrier function of fattening cattle,the herbal tea residue may affect intestinal tissue morphology and barrier function by changing the composition and relative abundance of jejunal flora,and ultimately promote the intestinal health.Chinese Journal of Animal Nutrition,2022,34(2):1087-1097]