Nutrient Requirements of Exercising Swamp Buffalo, Bubalus bubalis, from Materials Balance and In Vivo Body Composition by the Body Density Method. I. Aspects of Energy and Protein Metabolism in Working Cows |
I G. Mahardika, D. Sastradipradja, T. Sutardi, I K. Sumadi |
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Abstract |
Four young swamp buffalo cows of similar age ranging in weight between 280 to 380 kg and trained to do physical work were used in a study to determine energy and protein requirements for draught using a 4횞4 Latin square designed experiment. The experiment consisted of field trials employing 4 levels of work load, e.g. no work as control, and loads amounting 450 to 500 Newton (N) pulled continuously for 1, 2 and 3 h daily for 14 consecutive days. Cows were fed king grass (Penisetum purpuroides) ad libitum and were subjected to materials balance trials. Body composition was estimated in vivo by the body density method and daily energy expenditure (EE) was calculated from ME minus retained energy (RE). The results show that EE while not working (EEresting) was 0.42 kgW0.75 MJ/d and maintenance ME (MEm) was 0.37 kgW0.75 MJ/d. ME requirement increased to 1.65 times maintenance for the work of 3 hours. The energy expended for doing exercise (Eexercise) was 9.56, 20.0 and 25.86 MJ/cow for treatments 1, 2 and 3 h, respectively. Fat retention was absent in all groups of working cows, but protein retention was only negative for cows undertaking 3 h work. The relationship between Eexercise (MJ), work load (F, kN), work duration (t, h) and body mass (W, kg) was found to be: Eexercise=(0.003F1.43t0.93)/W0.09 MJ. The maintenance requirement for digestible protein was 2.51 kgW0.75 g/d, whereas digestible protein for growth (DPgrowth) and for work (DPwork) followed the equations: DPgrowth=[(258+1.25W0.75) Wkg/d]g and DPwork=[12.59e0.95t]g, respectively The coefficients a, b and c for the calculation of Eexercise components according to the Lawrence equation were found to be 2.56 J/kgW.m, 5.2 J/kg load carried.m and 0.29, respectively, thus efficiencies to convert ME into work were 0, 16.09, 27.3 and 32.44% for control, 1, 2 and 3 h/d work, respectively. ME and DP requirements for a 250 to 400 kg working buffalo cow allowing to growth up to 0.5 kg/d are presented |
Keywords:
Swamp Buffalo; Field Balance Trial; ME and Protein Requirements; Exercise; In Vivo Body Composition |
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