摘要
Considerable interest exists both from an environmental and economic perspective in reducing methane emissions from agriculture. In ruminants, CH4 is produced by a complex community of microorganisms that is established in early life but can be influenced by external factors such as feed. Although CH4 emissions were thought to be constant once an animal reached maturity, recent studies have shown that CH4 yield significantly increases from early to late lactation in dairy cows. The aim of this study was to test the hypothesis that increases in CH4 yield over the lactation cycle are related to changes in rumen microbial community structure. Nine cows were monitored throughout their first lactation cycle. Methane and dry matter intake were measured to calculate CH4 per dry matter intake (CH4 yield) and ruminal fluid was collected during early, mid, and late lactation. A significant difference in bacterial and archaeal community structure during early and late lactation was observed. Furthermore, when ruminal short-chain fatty acid concentrations were measured, the ratio of acetate and butyrate to propionate was significantly higher in late lactation compared with early lactation. Propionate concentrations were higher in cows with low CH4 yield during late lactation, but no differences were observed in bacterial or archaeal community structures. Prevotella dominated the rumen of cows followed by Succinclasticum; Treponema, Fibrobacter, Ruminococcus, and Bifidobacterium were also in high abundance relative to other bacterial genera. In general, positive correlations were stronger between the most relatively abundant bacterial genera and acetate and butyrate concentrations in the cows with high CH4 and weaker between these genera and propionate concentration. This study indicates that increased CH4 yield in late lactation is reflected in significant changes in microbial community structure.
摘要译文
从减少农业甲烷排放的环境和经济角度都存在着相当大的兴趣。在反刍动物中，CH 4由早期建立的复杂微生物群落产生，但可能受外部因素如饲料的影响。尽管一旦动物达到成熟期，CH 4排放被认为是恒定的，但最近的研究表明，奶牛的CH 4产量从泌乳早期到晚期显着增加。这项研究的目的是为了检验这一假设，即在泌乳周期中CH 4产量的增加与瘤胃微生物群落结构的变化有关。在第一次泌乳周期期间监测九头母牛。测量甲烷和干物质摄入量以计算每干物质摄入量的CH 4（CH 4产量），并且在泌乳早期，中期和晚期收集瘤胃液。观察到泌乳早期和晚期的细菌和古菌群落结构存在显着差异。此外，当测量瘤胃短链脂肪酸浓度时，与泌乳早期相比，泌乳后期乙酸盐和丁酸盐与丙酸盐的比例显着升高。泌乳晚期CH4产量低的母牛丙酸盐浓度较高，但在细菌或古菌群落结构中没有观察到差异。Prevotella主导了奶牛的瘤胃，其次是Succinclasticum;相对于其他细菌属，密螺旋体，纤维杆菌，瘤胃球菌和双歧杆菌也是高丰度的。一般来说，在CH4高的奶牛中，相对丰富的细菌属和醋酸和丁酸浓度最高，而这些属和丙酸浓度较弱。这项研究表明，哺乳期后期CH 4产量的增加反映了微生物群落结构的显着变化。
TamsinLyons[*][1];AnitaBielak[†][1];EvelynDoyle[*];BjörnKuhla[*];. Variations in methane yield and microbial community profiles in the rumen of dairy cows as they pass through stages of first lactation[J]. Journal of Dairy Science, 2018,101(6): 5102-5114