Schrama J W, van der Hel W, Arieli A, Verstegen M W
Department of Animal Husbandry, Agricultural University, Wageningen, The Netherlands.
J Anim Sci. 1992 Aug;70(8):2527-32. doi: 10.2527/1992.7082527x.
A study was conducted with seven groups of five to six Holstein-Friesian male calves to evaluate the effect of feeding level during 6 to 14 d of age on energy metabolism of unadapted young calves. Calves were transported at 2 to 3 d of age to their new environment. At 6 d of age measurements of heat production (HP) and ME intake started and continued over a period of 8 d. Calves were fed below (four groups) or near (three groups) the maintenance requirement (19 or 30 g of milk replacer powder.kg-.75.d-1). In contrast to ME intake, HP decreased throughout the experimental period. This decrease was larger at the low than at the high feeding level (3.1 vs .9 kcal.kg-.75.d-2; P less than .001). The relationship between HP and ME intake was estimated as HP = 91 + .318 x ME intake (kilocalories.kilogram-.75.day-1). The decrease in HP, together with the constant ME intake with time, resulted in a time-dependent relationship between HP and ME intake. Estimated basal metabolic rate and efficiency of ME utilization below maintenance decreased with time, whereas the maintenance requirement remained virtually unchanged (134 kcal.kg-.75.d-1). The influence of feeding level on energy metabolism in young calves increased with time. For at least 12 d after transportation the energy metabolism of young calves had not reached steady-state levels.
对七组每组五到六头荷斯坦 - 弗里生公牛犊进行了一项研究，以评估6至14日龄期间的饲喂水平对未适应新环境的幼龄犊牛能量代谢的影响。犊牛在2至3日龄时被转运到新环境。在6日龄时开始测量产热量（HP）和代谢能摄入量，并持续8天。犊牛被饲喂低于（四组）或接近（三组）维持需要量（分别为19或30克代乳粉·千克^-0.75·天^-1）。与代谢能摄入量不同，整个实验期间产热量下降。低饲喂水平下的下降幅度大于高饲喂水平（3.1对0.9千卡·千克^-0.75·天^-2；P小于0.001）。产热量与代谢能摄入量之间的关系估计为HP = 91 + 0.318×代谢能摄入量（千卡·千克^-0.75·天^-1）。产热量的下降，加上代谢能摄入量随时间保持恒定，导致产热量与代谢能摄入量之间呈现出随时间变化的关系。低于维持需要量时，估计的基础代谢率和代谢能利用效率随时间下降，而维持需要量实际上保持不变（134千卡·千克^-0.75·天^-1）。饲喂水平对幼龄犊牛能量代谢的影响随时间增加。运输后至少12天内，幼龄犊牛的能量代谢未达到稳态水平。
