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The Efficiency of utilization of metabolizable energy of milk-replacer-fed calves at weaning period |
J. Sekine, Z. Morita, R. Oura, T. Morooka, Y. Asahida |
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Abstract |
A total of 22 energy balance trials were done for calves fed a liquid milk replacer, calf starter and second cut mixed hay during weaning period. Milk replacer supplied 50% of the total dietary energy, calf starter 42% and hay 8%. Live weight of calves averaged 64.6 (S.D. ?? 7.8) kg and daily gain 0.54 (?? 0.22) kg. The metabolizability of gross energy averaged 0.751. A regression was calculated relating energy retention (ER, kJ/kg0.75) to the intake of metabolizable energy (IME, kJ/ kg0.75): ER = 0.69(?? 0.09) IME - 395, r = 0.888, P<0.01, S.E. ?? 7.1 Metabolizable energy for maintenance (MEm) was calculated to be 572 kJ/ kg0.75 when ER = 0. The amount of IME over MEm for an individual animal (MEg, kJ/ kg0.75) was regressed on average daily gain (ADG, kg) by the method of regression through the origin: MEg = 364(?? 55) ADG, r = 0.634, P<0.01, S.E. ?? 12. The amount of ME required for maintenance and growth was estimated to be 936 kJ/ kg0.75. |
Keywords:
Weaning Calves; Metabolizable Energy; Metabolizability; Maintenance |
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