Role of ruminants
Ruminants play an important role in global food security and nutrition, as well as in the livelihoods of farmers and those along the agrifood chain. Ruminant animals include cattle, sheep, goats and buffalo and are the largest livestock production system in the world. Over 50 percent of all protein supplied from the livestock sector comes from ruminants, mainly in the form of milk and meat.
One of the primary differences between ruminant and non-ruminant species is the structure of the stomach and consequently the digestive system, which is more complex and four-phased in ruminant animals. The enteric fermentation process naturally occurring in ruminants is one of the main drivers of methane emissions globally. Globally, enteric methane emissions from ruminants and manure management practices account for over 30 percent of all human-induced methane emissions. Cattle account for 77 percent of methane emissions, buffalo for 14 percent and small ruminants, such as sheep and goats for the remainder.
Usually ruminant production systems with low productivity, mainly found in low and middle income countries and regions, tent to lose more energy per unit of animal product than those with high productivity. Farming systems that are more productive generally have higher total methane emissions but much lower emissions per unit of product. This strong correlation between increased animal productivity and enteric methane emission reductions implies there are large opportunities for low-cost mitigation and widespread social and economic benefits.
FAO is helping countries identify mitigation opportunities and design intervention strategies to improve ruminant productivity and reduce enteric methane emissions in the livestock sector. The relatively short atmospheric lifetime of methane, combined with its strong warming potential, means that targeted strategies to reduce emissions can provide climate and health benefits within a few decades.
Resources
- Greenhouse gas emissions and fossil energy demand from small ruminant supply chains
- Environmental performance of large ruminant supply chains
- Climate change and the global dairy cattle sector