Nocek J E, Braund D G
J Dairy Sci. 1986 Jul;69(7):1871-83. doi: 10.3168/jds.S0022-0302(86)80613-0.
Holstein calves were assigned to one of three regimens from d 4 to 35 of age, then abruptly weaned (program 1): A) conventional, all-milk protein milk replacer fed individually twice daily; B) ad libitum feeding of cold, acidified milk replacer to calves housed and fed individually in pens, and C) same as B, except calves were housed and fed in group pens. From d 36 of age to 136 kg of body weight calves were in group pens by treatment. Program 2 utilized the same treatments; however, acidified milk replacer calves were gradually weaned starting d 22 of age. For program 1, calves fed acidified milk replacer for ad libitum intake consumed more dry matter from liquid and less from grain than those fed conventionally. Calves fed acidified milk replacer showed improved gains of 8.7 and 8.4 kg up to d 35 of age. For program 2, dry matter intake from liquid was higher, and grain was lower for calves fed acidified milk replacer; however, differences were not as large as in program 1. Body weight gains were 1.1 and 2.8 kg higher for calves fed acidified milk replacer through d 35 of age. No mortality occurred with either program during preweaning. In both programs, fecal consistency was more fluid for calves fed acidified milk replacer; however, days calves were treated were less. Regardless of preweaning program, calves on all treatments reached 136 kg of body weight in approximately the same number of days.
荷斯坦犊牛在4日龄至35日龄被分配到三种饲养方案之一，然后突然断奶（方案1）：A）传统方式，全乳蛋白代乳粉，每天分两次单独饲喂；B）犊牛单独饲养在栏舍中，自由采食冷的酸化代乳粉，每天单独饲喂；C）与B相同，只是犊牛成群饲养在栏舍中并成群饲喂。从36日龄到体重达到136千克，犊牛按处理方式成群饲养在栏舍中。方案2采用相同的处理方式；然而，酸化代乳粉组的犊牛从22日龄开始逐渐断奶。对于方案1，自由采食酸化代乳粉的犊牛从液体中摄入的干物质比传统饲养的犊牛多，从谷物中摄入的干物质少。自由采食酸化代乳粉的犊牛在35日龄前体重增加了8.7千克和8.4千克。对于方案2，自由采食酸化代乳粉的犊牛从液体中摄入的干物质较多，从谷物中摄入的较少；然而，差异没有方案1那么大。到35日龄时，自由采食酸化代乳粉的犊牛体重增加分别高出1.1千克和2.8千克。断奶前两个方案均未发生死亡。在两个方案中，自由采食酸化代乳粉的犊牛粪便更稀；然而，接受处理的天数较少。无论断奶前方案如何，所有处理组的犊牛达到136千克体重所需的天数大致相同。
