Department of Animal Science, Aarhus University, DK-8830 Tjele, Denmark.
Center for Quantitative Genetics and Genomics, Department of Molecular Biology and Genetics, Aarhus University, Tjele, Denmark.
J Dairy Sci. 2018 Nov;101(11):9847-9862. doi: 10.3168/jds.2017-14366. Epub 2018 Aug 29.
In the present study, we hypothesized that the rumen bacterial and archaeal communities would change significantly over the transition period of dairy cows, mainly as an adaptation to the classical use of low-grain prepartum and high-grain postpartum diets. Bacterial 16S rRNA gene amplicon sequencing of rumen samples from 10 primiparous Holstein dairy cows revealed no changes over the transition period in relative abundance of genera such as Ruminococcus, Butyrivibrio, Clostridium, Coprococcus, and Pseudobutyrivibrio. However, other dominant genus-level taxa, such as Prevotella, unclassified Ruminococcaceae, and unclassified Succinivibrionaceae, showed distinct changes in relative abundance from the prepartum to the postpartum period. Overall, we observed individual fluctuation patterns over the transition period for a range of bacterial taxa that, in some cases, were correlated with observed changes in the rumen short-chain fatty acids profile. Combined results from clone library and terminal-restriction fragment length polymorphism (T-RFLP) analyses, targeting the methyl-coenzyme M reductase α-subunit (mcrA) gene, revealed a methanogenic archaeal community dominated by the Methanobacteriales and Methanomassiliicoccales orders, particularly the genera Methanobrevibacter, Methanosphaera, and Methanomassiliicoccus. As observed for the bacterial community, the T-RFLP patterns showed significant shifts in methanogenic community composition over the transition period. Together, the composition of the rumen bacterial and archaeal communities exhibited changes in response to particularly the dietary changes of dairy cows over the transition period.
在本研究中，我们假设瘤胃细菌和古菌群落将随着奶牛的过渡阶段发生显著变化，主要是为了适应低谷物产前和高谷物产后日粮的经典使用。对 10 头初产荷斯坦奶牛瘤胃样本的 16S rRNA 基因扩增子测序表明，在过渡阶段，瘤胃中属水平的相对丰度如瘤胃球菌属、丁酸弧菌属、梭菌属、真杆菌属和拟丁酸弧菌属等没有变化。然而，其他优势属水平分类群，如普雷沃氏菌属、未分类的瘤胃球菌科和未分类的琥珀酸弧菌科，在后产阶段的相对丰度上表现出明显的变化。总的来说，我们观察到了一系列细菌分类群在过渡阶段的个体波动模式，在某些情况下，这些波动模式与瘤胃短链脂肪酸谱的观察变化相关。结合克隆文库和末端限制性片段长度多态性（T-RFLP）分析的结果，针对甲基辅酶 M 还原酶α亚基（mcrA）基因，揭示了以甲烷杆菌目和甲烷甲烷球菌目为主的产甲烷古菌群落，特别是甲烷杆菌属、甲烷球菌属和甲烷球菌属。与细菌群落一样，T-RFLP 模式显示了产甲烷菌群落组成在过渡阶段的显著变化。总之，瘤胃细菌和古菌群落的组成变化是对奶牛过渡阶段特别是日粮变化的响应。
