A few related points
Livestock rearing has been an integral part of the agricultural system in India. Currently, India possesses the world's largest livestock population of 485 million, which accounts for 13% of the global livestock population2. It has 57% of the world's buffalo and 16% of the cattle population. It ranks first with respect to cattle and buffalo population, second in goat, third in sheep and camel, and seventh in poultry populations in the world.
Methane is an important greenhouse gas which significantly contributes to global warming. Livestock is a major anthropogenic source of methane emission from agriculture.
The detailed state/district-level methane emission inventory by age-groups, indigenous and exotic breeds of different livestock categories was estimated using the country-specific and Indian feed standardbased emission coefficients and recent livestock census 2003. The total methane emission from Indian livestock, which includes enteric fermentation and manure management, was 11.75 Tg for 2003. Enteric fermentation accounts for 10.65 Tg (~91%) compared to 1.09 Tg (~9%) by manure management. Dairy buffalo and indigenous dairy cattle together contribute 60% of the total methane emission. The three high methane emitter states are Uttar Pradesh (14.9%), Rajasthan (9.1%) and Madhya Pradesh (8.5%).
Methane emissions from livestock have two components: emission from 'enteric fermentation' and 'manure management'. Ruminant animals, particularly cattle, buffalo, sheep, goat and camel produce significant amounts of methane under anaerobic conditions as part of their normal digestive processes. This microbial fermentation process, referred to as 'enteric fermentation', produces methane as a byproduct, which is released mainly through eructation and normal respiration, and a small quantity as flatus. Methane is also produced during anaerobic decomposition of livestock manure by anaerobic and facultative bacteria.