ABSTRACT

Thirty-one strains of propionic acid bacteria were screened for their effects on methane production and volatile fatty acid concentrations using in vitro assays of rumen fluid from Norwegian dairy cows and a grass silage–concentrate mixture as substrate. Nine of 31 strains were further analysed for effects on substrate degradation. Propionic acid bacteria led to reductions of up to 20% in methane production. Seven strains stimulated volatile fatty acid production, and in their presence in vitro substrate degradation tended to increase (P < .10). Most consistent results were found with Propionibacterium thoenii T159, which reduced methane production by 20% and caused 8% and 21% overall increases in substrate degradation and total volatile acid production, respectively (P < .05). Concomitant beneficial effects of a reduction in methane emissions and an increase in feed degradation suggest that this strain may be a promising tool for improving the productive performance of dairy cows.

摘要

使用来自挪威奶牛的瘤胃液和草青贮浓缩液混合物作为底物的体外测定，筛选了31株丙酸细菌对甲烷产生和挥发性脂肪酸浓度的影响。进一步分析了31个菌株中的9个对底物降解的影响。丙酸细菌导致甲烷产量减少多达20％。七个菌株刺激了挥发性脂肪酸的产生，在体外存在的情况下，底物降解趋于增加（P  <.10）。发现与苏氏丙酸杆菌最一致的结果T159可将甲烷产生量降低20％，并分别导致底物降解和总挥发性酸产生量分别增加8％和21％（P  <.05）。甲烷排放量减少和饲料降解增加的同时带来的有益影响表明，该菌株可能是提高奶牛生产性能的有前途的工具。