Strategies for mitigating methane emissions from livestock - Australian options and opportunities

Methane produced by enteric fermentation within the digestive tract of sheep and cattle is the largest source of agricultural methane emissions in Australia and contributes 13.2 % of total national greenhouse gas emissions. Reducing emissions from this sector by nutritional management, animal selection and rumen modification are possible, but require a long-term research and development commitment. While rumen modification and animal selection offer direct tools to reduce daily methane emissions from domestic ruminants, feed management does not offer such a simple solution to achieve reduced annual methane emissions from the livestock sector. A continual focus on the improved production efficiency resulting from improved diet digestibility (g methane/g product) is considered unhelpful in achieving reduced emissions from the sector unless incentives to decrease livestock numbers are also implemented. An array of opportunities for animal selection and rumen modification are discussed and their development is recommended to create 'enviromnent-friendly' livestock.