本试验旨在通过体外培养法研究大蒜油和脱臭大蒜油对瘤胃发酵、甲烷生成和微生物区系的影响。在体外培养过程中用压力读取式法（RPT系统）测定产气量，利用气相色谱仪测定甲烷产量。培养24 h后，测定挥发性脂肪酸、pH、氨态氮浓度，并用实时荧光定量PCR测定瘤胃微生物区系。研究发现，与对照组相比，添加大蒜油极显著降低甲烷产量（P<0.01），显著降低乙酸摩尔百分比和氨态氮浓度（P<0.05），显著提高丙酸摩尔百分比（P<0.05），对产气量和总挥发性脂肪酸含量也有显著地抑制作用（P<0.05），但抑制程度不如大蒜油对甲烷产量的抑制程度。添加脱臭大蒜油对甲烷产生也有一定作用，但效果不显著（P>0.05）。添加大蒜油和脱臭大蒜油后甲烷菌和原虫含量极显著降低（P<0.01），且大蒜油的抑制作用强于脱臭大蒜油（P<0.01）。试验结果表明：适宜浓度的大蒜油可以改变瘤胃发酵类型，增加丙酸摩尔百分比，显著抑制甲烷生成而不影响消化，这种改变与瘤胃微生物区系的变化密切相关；此外，大蒜油的作用效果明显强于脱臭大蒜油。

This study was conducted to evaluate effects of normal and deodorized garlic oil on rumen fermentation, methanogenesis and microbiota in vitro. Reading pressure technique system and gas chromatography were used to determine gas production and methane emission, respectively. Volatile fatty acids, pH and ammonia nitrogen were determined after 24 h incubation. Population of rumen microbiota was detected by real-time PCR assay. The results showed that addition of garlic oil significantly decreased methane production (P<0.01), acetate proportion and ammonia nitrogen (P<0.05), and increased propionate proportion (P<0.05). The gas production and total VFA concentration were influenced but the effect was less than that on the methane production. Addition of deodorized garlic oil tended to influence methane emission and gas production (P>0.05). Whether adding normal or deodorized garlic oil, proportion of protozoa and methanogen related to total rumen bacterial 16S rDNA was decreased significantly (P<0.01), with a stronger effect by garlic oil than that by deodorized one (P<0.01). In conclusion, addition of garlic oil at a proper level could change the fermentation pattern, increase the proportion of propionate to acetate, and inhibit methanogenesis. These were associated with the change of microbiota in the rumen. Normal garlic oil had a stronger effect than the deodorized one.［Chinese Journal of Animal Nutrition, 2010，22（2）:386-392］