van den Borne J J G C, Verstegen M W A, Alferink S J J, Giebels R M M, Gerrits W J J
Animal Nutrition Group, Department of Animal Sciences, Wageningen University, 6700 AH Wageningen, The Netherlands.
J Dairy Sci. 2006 Sep;89(9):3578-86. doi: 10.3168/jds.S0022-0302(06)72397-9.
The objective of this study was to determine the effects of feeding frequency (FF) and feeding level (FL) on protein and energy metabolism in adapted, heavy preruminant calves. It was hypothesized that an increased FF would increase protein utilization by an improved synchrony between the supply of and requirements for protein during the day when a quickly hydrolyzable protein source was used. Eighteen Holstein Friesian calves of 136 +/- 3 kg of body weight were assigned to FF (1, 2, or 4 meals daily) at 2 FL (1.5 or 2.5 times the metabolizable energy requirements for maintenance), except for calves fed once daily (only at a low FL). Calves were individually housed in respiration chambers during 2 experimental periods of 10 d. Whey protein was the only protein source in the diet. Neither FL nor FF affected apparent fecal nutrient digestibility. Increasing FF increased the efficiency with which digestible protein was utilized in calves. The increase was greater at a high FL (+11% from 2 to 4 meals/d) than at a low FL (+5% from 2 to 4 meals/d), but no significant interaction occurred between FL and FF. An increased FF and a higher FL enhanced fat deposition. Heat production was not affected by FF, but its circadian rhythm differed considerably between FF. Activity-related heat production was not affected by FF or FL. Thus, increasing FF improved the efficiency with which protein and energy were utilized in heavy preruminant calves when a quickly hydrolyzable protein source was used.
本研究的目的是确定饲喂频率（FF）和饲喂水平（FL）对适应环境的重胎犊牛蛋白质和能量代谢的影响。研究假设，当使用快速水解的蛋白质来源时，增加FF会通过改善白天蛋白质供应与需求之间的同步性来提高蛋白质利用率。18头体重为136±3 kg的荷斯坦弗里生犊牛被分配到FF组（每日1、2或4餐），有2个FL水平（维持代谢能需求的1.5倍或2.5倍），但每天饲喂一次的犊牛（仅处于低FL水平）除外。在两个为期10天的试验期内，犊牛被单独饲养在呼吸室内。乳清蛋白是日粮中唯一的蛋白质来源。FL和FF均未影响表观粪便养分消化率。增加FF提高了犊牛对可消化蛋白质的利用效率。在高FL水平下增加幅度更大（从每日2餐增加到4餐提高11%），而在低FL水平下增加幅度较小（从每日2餐增加到4餐提高5%），但FL和FF之间未发生显著交互作用。增加FF和提高FL增强了脂肪沉积。产热不受FF影响，但其昼夜节律在不同FF之间有很大差异。与活动相关的产热不受FF或FL影响。因此，当使用快速水解的蛋白质来源时，增加FF提高了重胎犊牛蛋白质和能量的利用效率。
