Nitrate suppresses methane production by acting as a
hydrogen sink as well as directly inhibiting the methano-
gens (
Patra and Yu, 2013
). Addition of fumarate that is an
intermediate of propionate production enhances propio-
nate concentration with a stoichiometric decrease in
hydrogen availability for methane synthesis (
Kolver et al.,
2004
). Fumarate and nitrate have been evaluated widely
for nutrient utilization and rumen fermentation in rumi-
nants (
Kolver et al., 2004
;
Patra and Yu, 2013
), but not in
tree leaves-based diets.
P. cineraria
and
A. excelsa
foliages
have shown to lower enteric methane production addi-
tively along with nitrate and fumarate in vitro (
Pal et al.,
2014
). Thus, the objective of this study was to investigate
the effects of combinations of
A. excelsa
and
P. cineraria
leaves plus nitrate or fumarate on nutrient utilization,
rumen fermentation, microbial protein supply and blood
biochemical profile in sheep