Methane and climate change

The New Zealand government has indicated that it will ratify the Kyoto Protocol, which means that legally binding targets will be set for reducing greenhouse gas (GHG) emissions. In “preferred” policies to achieve these targets, the agricultural sector will not be taxed directly but is expected to contribute to research leading to methane mitigation. A wide range of possibilities other than reducing livestock numbers exist for lowering livestock methane emissions: increasing the efficiency of animal production, exploiting betweenanimal variation; anti-methanogenic feed additives; dietary manipulation, including pasture composition modification; immunisation; and, manipulation of the rumen microbial ecosystem. Reduction in methane will not only have global environmental benefits, but also, as methane represents a loss of about 6% of an animal’s energy intake, any reduction should be reflected in increased animal productivity per unit of intake. It should be possible to deliver a win/win situation with respect to methane reduction and increased productivity.