Methanogenesis and its mitigation in ruminants

Rumen micro-organisms play a crucial role in all ruminants for efficient utilization of complex plant materials. As by-product of rumen anaerobic fermentation, methane is emitted which is considered to be a potent global warming agent and most abundance in concentration, after carbon dioxide. Improved economic states and increasing human population will inflate animal product demands, culminating in elevated levels of methane emissions from livestock component of agriculture sector. Methods to reduce enteric methane include genetic manipulations, use of feed additives, defaunation, plant secondary metabolites and dietary alterations. Some strategies are highly valuable in terms of methane reductions but more intensive in-vivo research studies are required for their practical use and on-farm implementations. Ideal method would reduce methane levels effectively without altering optimum productive capacity of animal and its overall performance.