PDF(Pubmed)
Abstract：
Ruminal methane production is the main sink for metabolic hydrogen generated during rumen fermentation, and is a major contributor to greenhouse gas (GHG) emission. Individual ruminants exhibit varying methane production efficiency; therefore, understanding the microbial characteristics of low-methane-emitting animals could offer opportunities for mitigating enteric methane. Here, we investigated the association between rumen fermentation and rumen microbiota, focusing on methane production, and elucidated the physiological characteristics of bacteria found in low methane-producing cows. Thirteen Holstein cows in the late lactation stage were fed a corn silage-based total mixed ration (TMR), and feed digestion, milk production, rumen fermentation products, methane production, and rumen microbial composition were examined. Cows were classified into two ruminal fermentation groups using Principal component analysis: low and high methane-producing cows (36.9 vs. 43.2 L/DMI digested) with different ruminal short chain fatty acid ratio [(C2+C4)/C3] (3.54 vs. 5.03) and dry matter (DM) digestibility (67.7% vs. 65.3%). However, there were no significant differences in dry matter intake (DMI) and milk production between both groups. Additionally, there were differences in the abundance of OTUs assigned to uncultured Prevotella sp., Succinivibrio, and other 12 bacterial phylotypes between both groups. Specifically, a previously uncultured novel Prevotella sp. with lactate-producing phenotype was detected, with higher abundance in low methane-producing cows. These findings provide evidence that Prevotella may be associated with low methane and high propionate production. However, further research is required to improve the understanding of microbial relationships and metabolic processes involved in the mitigation of enteric methane.
摘要：
瘤胃甲烷的产生是瘤胃发酵过程中产生的代谢氢的主要汇，并且是温室气体（GHG）排放的主要贡献者。个体反刍动物表现出不同的甲烷生产效率；因此，了解低甲烷排放动物的微生物特征可以为减轻肠道甲烷提供机会。这里,我们调查了瘤胃发酵和瘤胃微生物群之间的关系，专注于甲烷生产，并阐明了在低产甲烷奶牛中发现的细菌的生理特性。哺乳后期的13头荷斯坦奶牛饲喂以玉米青贮为基础的总混合日粮（TMR），和饲料消化，牛奶生产,瘤胃发酵产品，甲烷生产，和瘤胃微生物组成进行检查。使用主成分分析将奶牛分为两个瘤胃发酵组：产甲烷低和高（36.9与43.2L/DMI消化），不同瘤胃短链脂肪酸比例[（C2+C4）/C3]（3.54vs.5.03）和干物质（DM）消化率（67.7％vs.65.3%）。然而,两组之间的干物质摄入量(drymatteraction,drawproduction)和产奶量没有显著差异.此外,分配给未培养的Prevotellasp。的OTU丰度存在差异。,丁氏弧菌,两组之间的其他12种细菌表型。具体来说,一个以前未培养的小说普雷沃氏菌。检测到产生乳酸的表型，甲烷产量低的奶牛的丰度较高。这些发现提供了证据，证明Prevotella可能与低甲烷和高丙酸盐产量有关。然而,需要进一步的研究，以提高对肠道甲烷缓解过程中涉及的微生物关系和代谢过程的理解。
