Methane is the second largest anthropogenic GHG, which contributes
14.3% of total anthropogenic GHG emissions (
IPCC, 2007
).
Indian livestock accounts for about 13.9% of the global enteric
methane emission (global enteric methane emission of
85.63 Tg/year) and the enteric methane emission has been
projected to be 12,848 Gg in 2012, and this could be increased
to 14,553 Gg in 2020 without proper mitigation measures
(
Patra, 2012
). Most of the CH
4
from ruminant livestock
originates from microbial fermentation of carbohydrates in
the rumen, which also accounts for a substantial gross energy
loss of feeds depending upon the types of diets. Therefore,
inhibition of CH
4
production in the rumen had been
attempted to increase the utilization of feed energy for
production purpose and mitigate GHG emissions. A number
of methane mitigation strategies have been evaluated in
ruminants