The use of feed supplements to reduce livestock greenhouse gas emissions: direct-fed microbials

This chapter aims to outline the strategy of using feed supplements for the reduction of greenhouse gas emissions (GHG) in ruminants, including methane (CH4), carbon dioxide and nitrous oxide, given that feed intake is an important variable in predicting these emissions. Focus will be given to direct-fed microbials, a term reserved for live microbes which can be supplemented to feed to elicit a beneficial response. The viability of such methods will also be analysed for their use in large scale on-farm operations.