These values were relatively lower than
the value suggested by Crutzen et al.4 estimated from the
study of Krishna et al.11. Kurihara et al.12 measured methane production by Brahman cattle given either Angleton
grass (CP 2.4%) or Rhodes grass (CP 8.9%) and energy
loss as methane was 10.4 and 11.4%. Mohini and Singh14
reported that energy loss as methane had amounted to
3.0–3.2% of GE in buffalo calves given green jowar ad
libitum. While, Mohini and Singh15 also reported wide
variation of energy loss as methane that amounted to 4.8–
9.7% of GE in buffalo calves given concentrate feed and
maize fodder. During our respiration trial, the change of
oxygen consumption showed constant rhythm consistent
with breath in both animals, which was considered to
confirm that the animals adapted well to the mask and
behaved ordinarily.