【摘要】 试验旨在研究枯草期放牧东宝黑头羊瘤胃内环境参数及瘤胃细菌多样性。采集枯草期牧草样品,测定常规营养成分含量,选取6只体重为（45.24±1.25）kg的2岁全年放牧的东宝黑头羊（公母各半）,进行耳牌标记,在枯草期放牧前空腹经口腔采集瘤胃液,用于分析瘤胃内环境参数和瘤胃细菌多样性。结果表明,东宝黑头羊瘤胃液pH为6.65,氨态氮（NH3-N）浓度50.30 mg/L,乙酸/丙酸4.43;6个样本共获得290 868条高质量16S rDNA序列,479.67个分类操作单元（OTU）,东宝黑头羊瘤胃细菌丰富度指数Ace指数、Chao1指数分别为523.31、533.79,α-多样性指数Shannon指数、Simpson指数分别为6.39、0.96;经物种注释,共有15个门23个纲29个目34个科87个属被鉴定。在门水平,拟杆菌门（Bacteroidetes,75.75%）、厚壁菌门（Firmicutes,15.62%）含量最多;在科水平,主要包括理研菌科（Rikenellaceae,45.89%）、普雷沃氏菌科（Prevotellaceae,19.18%）;在属水平,理研菌科RC9肠道群（Rikenellaceae_RC9_gut_group,45.64%）、普雷沃氏菌属（Prevotella₁,15.46%）是放牧东宝黑头羊瘤胃中的优势种群。结果证明,枯草期放牧东宝黑头羊瘤胃细菌多样性较低;乙酸/丙酸比值较高;东宝黑头羊瘤胃中最优势菌门为拟杆菌门,其次是厚壁菌门;理研菌科RC9肠道群是东宝黑头羊瘤胃中最优势细菌属。更多还原

【Abstract】 The aim of this experiment was to study ruminal environment and rumen bacterial diversity of grazing Dongbao blackhead goats in grass withering period. The forge grass were collected and the common nutrition contents were determined. Six healthy annual grazing Dongbao blackhead goats（3 males and 3 females）with the body weight of（45.24±1.25）kg were selected and marked using ear tags with numbers,and the rumen fluids of them were collected via oral cavity before free-range with empty stomach in grass withering period to measured the ruminal environment parameters and rumen microbial diversity. The results showed that the pH of rumen fluid of Dongbao blackhead goats was 6.65,the concentration of ammonia nitrogen（NH3-N）was 50.30 mg/L,and the ratio of acetic acid/propionic acid was 4.43. A total of 290 868 valid 16 S rDNA sequences and 479.67 operational taxonomic unit（OTU）across 6 samples were obtained. The richness indexes Ace and Chao1 indexes of ruminal bacterial were 533.79 and 523.31,respectively,and alpha diversity indexes Shannon and Simpson indexes were 6.39 and 0.96,respectively. The rumen bacteria of grazing Dongbao blackhead goats belonging to 15 phyla,23 classes,29 orders,34 families and 87 genera were identified via taxonomic summary. Among these rumen bacterial populations,the dominant bacterial phyla were Bacteroidetes（75.75%）and Firmicutes（15.62%）. The dominant bacterial families were Rikenellaceae（45.89%）,Prevotellaceae（19.18%）. Rikenellaceae_RC9_gut_group（45.64%）and Prevotella₁（15.46%）were the dominant bacterial genera. In conclusion,the rumen bacterial diversity of grazing Dongbao blackhead goats was low in grass withering period,and the ratio of acetic acid/propionic acid was high. Bacteroidetes is the predominant phylum and Firmicutes is the second most abundant phylum. Rikenellaceae_RC9_gut_group is the most abundant genus in the rumen bacterial community.更多还原