Efficiency of N utilization under controlled temperature and humidity conditions in a respiration chamber was studied at similar N supply levels provided through feeding decorticated groundnut cake and wheat straw to adult male ruminants, 4 each, belonging to buffalo, Holstein and crossbred cattle categories.
N intake was 0.76, 0.71 and 0.73 g/kg W0.75 for buffaloes, Holstein and crossbred cattle, respectively. Corresponding N absorption was 50.84, 48.57 and 52.47% of N intake which was not significantly different among the species. The quantity of absorbed N was 0.39, 0.35 and 0.38 g/kg W0.75, respectively for the three species. Urinary N excretion of buffaloes, Holstein and crossbred cattle was similar at 0.22, 0.19 and 0.19 g/kg W0.75, respectively. The urinary N excretion after 96 hr of fasting was 0.23, 0.33 and 0.34 g/kg W0.75, (p>0.05). However, in either type of cattle, the urinary N excretion increased during fasting than feeding but remained similar in buffaloes.
