Methane (CH4) is the main electron sink in ruminal
fermentation. Its release to the atmosphere represents
an energy loss of between 2 and 15% of ingested gross
energy (Van Nevel and Demeyer, 1996) and also contributes
to global climate change (Moss, 1993). Therefore,
there is an interest in decreasing CH4 production in the
rumen for both environmental and economic reasons.