Regional Approach to Enteric Methane Estimation from Dairy Animals: A Case Study of Semi-arid Region of Rajasthan

Enteric methane emission accounts for about 17 per cent of national Green House Gas (GHG) emissions and 60 percent of the GHG emissions from agriculture sector in India. As the losses of methane represent inefficiencies and losses of energy in our current production system, it therefore stands to reason that estimates of enteric methane emission have long-run implications for environmental sustainability of dairy farming. The available literature is lacking in geographic region specific methane emission factor which varies based on quantity and quality of feed. Therefore, present study estimated the enteric methane emission from diary animals in semiarid eastern plain zone of Rajasthan using both primary as well as secondary data. The emission factor for each category of dairy animals was generated using the Tire-II approach proposed by Inter-governmental Panel on Climate Change based on primary data collected from 120 households of Jaipur district of the state selected purposively representing best case in the zone. The results of study showed that the methane factors for lactating local cow, crossbred cow and buffalo were 144.19g, 203.78g and 198.41g/head/day respectively, while dry local cow, crossbred cow and buffalo emitted 124.85g, 190.29g and 173.74g/head/day, respectively. The estimated methane emissions from enteric fermentation of dairy animals in the zone was 10308.37 thousand tones and more than 2/3^rd of which was contributed by buffaloes. The methane emission in relation to milk production was worked out 75.72 g/kg of milk and reported highest in case of crossbred cattle (147.56g/kg milk). Study suggests for incorporating energy efficient diets such as concentrates and by-products of sugar industry, maintaining the livestock population in relation to carrying capacity, improving the productivity on animals, etc. for reducing the methane emission in the zone.