Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain.
J Dairy Sci. 2010 Jan;93(1):413-9. doi: 10.3168/jds.2009-2682.
Two experiments were conducted to evaluate whether performance could be improved and incidence of respiratory problems decreased either by allocating 6 additional days of individual housing after weaning or by moving calves in groups before weaning at 2 different ages. The first experiment involved 320 female calves that received 2L of milk replacer (MR) twice daily until 49 d of age, and then 2L of MR once daily until weaning at 56 d of age. Half of the calves were allowed to remain individually housed for an additional 6d after weaning, and the other half were moved immediately after weaning to a different pen holding 8 calves. The second experiment involved 240 female calves that received 2L of MR twice daily until 49 d of age, and then 2L of MR once daily. Half of the calves were moved at 49 d of age to superhutches holding 8 calves with an elevated trough that was used to continue delivering MR; the other half remained individually housed until the age of 56d and were then moved to the superhutches, where they also continued to receive MR. Growth and incidence of respiratory problems were recorded in both experiments, and feed intake was recorded in experiment 2. Calves moved to groups immediately after weaning reached the target BW 6d earlier and experienced a lesser incidence of respiratory afflictions than those grouped 6d after weaning. From experiment 2, calves grouped at 49 d of age had a greater average daily gain and BW at 56 d of age as a result of a greater total solid feed consumption compared with those grouped at 56 d of age. Calves grouped at 56 d, however, had a greater average daily gain between 56 and 64 d of age (the week following grouping for the calves in the 56-d treatment) than those grouped at 49 d of age. Overall, the proportion of animals affected by a respiratory problem between 49 and 112 d of age did not differ between treatments. However, calves grouped at 49 d of age had a lower number of respiratory cases than those grouped at 56 d of age. It is concluded that moving calves from individual hutches to groups of calves in superhutches immediately after weaning is preferable to waiting an additional 6d. In addition, moving calves from individual hutches to groups of 8 in superhutches at 49 d of age and starting to reduce MR offering once grouped is preferable to starting to reduce MR while calves are individually housed.
进行了两项实验，以评估在断奶后分配 6 额外的单独饲养天数，或者在断奶前以 2 个不同年龄分群，是否可以提高性能并降低呼吸道问题的发生率。第一项实验涉及 320 头雌性犊牛，它们在 49 日龄前每天接受 2 升代乳料（MR）两次，然后在 56 日龄前每天接受 2 升 MR 一次。一半的犊牛在断奶后可以继续单独饲养 6 天，另一半在断奶后立即转移到另一个容纳 8 头犊牛的围栏中。第二项实验涉及 240 头雌性犊牛，它们在 49 日龄前每天接受 2 升 MR 两次，然后每天接受 2 升 MR 一次。一半的犊牛在 49 日龄时转移到容纳 8 头犊牛的超级畜栏中，畜栏中有一个抬高的食槽，用于继续提供 MR；另一半在 56 日龄前一直单独饲养，然后转移到超级畜栏，继续接受 MR。在这两项实验中都记录了生长和呼吸道问题的发生率，并在实验 2 中记录了饲料摄入量。断奶后立即分群的犊牛达到目标 BW 早了 6 天，并且呼吸道疾病的发病率低于断奶后 6 天分群的犊牛。从实验 2 来看，与 56 日龄分组的犊牛相比，49 日龄分组的犊牛由于总固体饲料摄入量增加，在 56 日龄时的平均日增重和 BW 更大。然而，56 日龄分组的犊牛在 56 至 64 日龄之间（56 日龄分组的犊牛分组后的第一周）的平均日增重更大。总体而言，在 49 至 112 日龄期间，受呼吸道问题影响的动物比例在处理之间没有差异。然而，与 56 日龄分组的犊牛相比，49 日龄分组的犊牛呼吸道病例较少。因此，结论是断奶后立即将犊牛从单独的畜栏转移到超级畜栏中的犊牛群体中比等待额外的 6 天更好。此外，与单独饲养的犊牛相比，在 49 日龄时将犊牛从单独的畜栏转移到超级畜栏中的 8 个畜栏中，并开始减少 MR 的供应，要优于在单独饲养的犊牛中开始减少 MR。
