中文摘要：

【目的】本试验通过对比健康与腹泻仔猪粪样挥发性脂肪酸（Volatile fatty acid,VFA）以及菌群的差异,初步探讨腹泻对仔猪后肠环境的影响。【方法】采集腹泻和健康仔猪粪样,气相色谱测定挥发性脂肪酸浓度;提取粪样总细菌核酸,利用变性梯度凝胶电泳（Denaturing gradient gel electrophoresis,DGGE）和Real-timePCR技术定性、定量分析总细菌和梭菌Ⅳ菌群。【结果】与健康仔猪相比,腹泻仔猪粪样中乙酸含量有升高的趋势,支链脂肪酸（Branched chain fatty acid,BCFA）含量显著降低（p〈0.05）,总VFA、丙酸和丁酸含量有降低的趋势,但差异均不显著;乙酸占总挥发酸比例显著升高（p〈0.05）,而丙酸及BCFA占总挥发酸比例则显著降低（p〈0.05）,丁酸占总挥发酸比例有降低趋势。PCR-DGGE指纹技术分析表明：腹泻发生后,仔猪粪样中总细菌和梭菌Ⅳ菌群在DGGE图谱上并没有特异性的条带消失或出现,但相似性分析显示,腹泻仔猪样品趋于归类于同一簇。Real-time PCR定量分析显示：仔猪腹泻后,粪样中的总细菌和梭菌Ⅳ菌群的数量显著下降（p〈0.05）;而大肠杆菌和乳酸杆菌的数量变化不显著。【结论】与健康仔猪相比,腹泻仔猪粪样挥发性脂肪酸组成发生改变,并且微生物区系中的一些菌群也发生变化。

英文摘要：

[Objective] To compare volatile fatty acid（VFA） concentration and microbiota in faeces between healthy and diarrhoeal piglets.[Methods] Fecal samples from healthy and diarrhoeal piglets were collected.VFA concentration was determined by GC analysis.Total bacterial DNA was extracted and used for molecular analysis of microbiota.[Results] As compared to healthy piglets,the concentration of acetate in feces of diarrhoeal piglets tended to increase,while branched chain fatty acid（BCFA） decreased significantly（p0.05）,total VFA（TVFA）,propionate and butyrate tended to decrease.The ratio of acetate to TVFA in faeces of diarrhoeal piglets was significantly higher than that in healthy piglets（p0.05）,while the ratio of propionate and BFVA to TVFA decreased significantly after diarrhoea（p0.05）.DGGE analysis of total bacterial community and Clostridium cluster Ⅳ group showed no significant changes in both bacterial community were found in faeces of piglets after diarrhoea.Similarity analysis of DGGE profiles revealed that faecal samples of diarrhoeal piglets tended to gather in the same cluster.Real-time PCR results showed that as compared to healthy piglets,the 16S rRNA gene copies of total bacteria and Clostridium cluster Ⅳ decreased significantly in faeces of piglets after Diarrhea（p0.05）,while there was no significant change in the numbers of E coli and Lactobacilli.[Conclusion] VFA composition in faeces of diarrhoeal piglets changed accompanying with the shift of microbiota as compared to healthy piglets.