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Methane (CH4) emission from ruminant livestock industry consist of 29% of total CH4 production in the world. The variation of different animal breeds in the production of CH4 may provide new opportunities for manipulating CH4 emissions. Six rumen-simulating fermenters (Rusitec) were set up for the study lasting for 16 d. The study diet contained forage to concentrate ratio of 50:50 with barley straw as the forage. Each three vessels received rumen fluid from yak and cattle, respectively. Microbial growth was measured using 15N as a marker. The microbe community structure from liquid and solid of each vessels were determined through 16S rRNA sequencing using MiSeq platform. Lower CH4 yield was found in yak compare with cattle (0.26 and 0.33 mmol CH4/g dry matter intake, respectively). The higher abundance of succinate- and lactate-producer genus Anaerobiospirillum, Streptococcus and Succinivibrio; propionate-producer genus Lactobacillus, hydrogen consumed genus included sulphate-reducing bacteria Desulfovibrio and acetogens Blautia were linked with lower CH4 production in yak. Bacteroides, Victivallis, Anaerosporobacter, Ruminococcus and Anaerovorax were correlated with cattle, which produce H2 as one of the main production. And the relative abundance of methanogen was higher in cattle. Thus, less H2 producer and CH4-producer; more H2 consumer existed in the rumen of yak contributed to the lower CH4 production. |