中文摘要：

本试验利用酵母培养物（yeast culture，YC）和延胡索酸二钠（disodium fumarate）的优化组合，研究该组合添加剂在慢性瘤胃酸中毒（subacute rumen acidosis．SARA）状态下对瘤胃发酵功能及瘤胃微生物数量的影响。选取6只泌乳期并安装永久性瘤胃瘘管的奶山羊，随机分为试验组和对照组，每组各3只，通过逐渐添加精料的方式诱导动物发生SARA。试验动物处于SARA后，试验组添加组合添加剂，测定瘤胃发酵指标。采用16S rRNA寡核苷酸探针杂交定量分析法和传统滚管法测定瘤胃内细菌的含量。结果表明，投喂组合添加剂后，瘤胃pH、乙酸、丁酸和总挥发性脂肪酸（total volatile fattyacids，TVFA）浓度显著升高（P〈0．05），丙酸和乙酸／丙酸没有显著变化（P〉0．05），NH3-N浓度显著降低（P〈0．05）。淀粉分解菌、反刍兽新月单胞菌、埃氏巨型球菌及3种主要纤维分解菌的数量显著增高（P〈0．05），乳酸杆菌、牛链球菌的数量显著降低（P〈0．05）。以上结果说明YC和延胡索酸二钠的组合使用能够改善SARA状态下瘤胃内环境，对减少SARA的发生具有较好的效果。

英文摘要：

The effects of adding both yeast culture （YC） and disodium fumarate to diets on ruminal fermentation and bacteria amounts in dairy goats suffered from subacute rumen acidosis （SARA） were investigated. Six lactating goats with permanent ruminal cannulas were induced SARA by gradually increasing feeding concentrate. The experimental animals were fed the combined additives when animals were in SARA period. The ruminal fermentation parameters were determined and the bactaria amounts were quantitated by the traditional roll-tube technique and 16S rRNA oligonecleotoide probes hybridization. After feeding the both additives,the pH,acetate, butyrate and total volatile fatty acid concentrations increased significantly （P〈0.05）, while propionate concentration and acetate/propionate ratio were not affected （P〉0.05）. The NH3-N concen- tration decreased significantly （P〈0.05）. The populations of amylolytic bacteria,S, ruminantium, M. elsdeni and the three kinds of predominant cellulose-decomposing bacteria increased significantly （P〈0.05）, while those of Lactobacillus and S. boris decreased significantly （P〈0.05）. It was concluded that adding both YC and disodium fumarate to diets of the dairy goats during induced SARA period could improve rumen internal environment and fermentation, which resulted in decreasing occurrence of SARA.