The objectives of the present study were to evaluate fasting heat Production (FP) and energy metabolism to evaluate comparative maintenance energy requirements for buffalo and cross bred cattle and to compare feeding systems for buffalo and cross bred cattle. Six buffalo and six cross bred cattle of same age group (about two years old) and average live body weight 348 and 240 kg respectively, were taken for the study. Prior to a 3-4 day fasting period, buffalo and cross bred cattle were offered a mixed diet of wheat straw and concentrates (of varying ratio on dry matter basis) for 21 days. Gas exchanges for each animal and urinary nitrogen excretion were determined for 2 days from day 3rd day of starvation, using open circuit respiration calorimetry. Mean oxygen consumption (1466 l/day and 1278 l/day), carbon dioxide production (1078 l/day and 939 l/day) and methane production nearly zero was obtained for buffaloes and crossbred cattle respectively. Mean fasting heat production of buffaloes and cross bred cattle were 68.16±0.01 and 74.48±0.90 (Kcal) Kg-1W0.75day-1.. Fasting heat production (FHP) found to be significantly (P< 0.05) higher for cross bred cattle than the buffalo group.
Key words: Buffaloes, Cross Bred Cattle, Metabolic Body Size, Fasting Heat Production, Net Energy, Maintenance