Reducing methane emissions in ruminants: is it an achievable goal?

Decreasing methane emissions and, more generally, decreasing the environmental footprint of ruminants is one pressing challenge facing the ruminant production sector. Notwithstanding, because of the intricate relationships existing between the efficiency of feed fermentation in the rumen and methanogenesis, mitigation options have to be evaluated not just in terms of their effect on methane or total GHG emissions but also on other rumen functional parameters and on their final consequences on animal production. The sustainability and profitability of the proposed mitigation options have to be considered as well. Several strategies that focus on the farm, the animal and the gastrointestinal microbes are currently being explored to decrease GHG emissions throughout the whole production cycle. Some of these strategies will be presented and discussed with a particular emphasis on the information available on technologies and feeding and management practices applicable to small ruminant production systems.