Department of Animal and Veterinary Sciences, Aarhus University, 8830 Tjele, Denmark.
J Dairy Sci. 2023 Dec;106(12):9598-9612. doi: 10.3168/jds.2023-23393. Epub 2023 Aug 23.
Allowing the dam to rear her calf is an alternative practice in the dairy industry where cow and calf may gain welfare benefits from performing natural and highly motivated behaviors. However, this system has been linked to an increased separation and weaning response. Reducing the daily dam-calf contact time may be a way to prepare the calf for weaning and separation. The first aim of the present study was to investigate the effect of 8 wk of half-day dam-calf contact on calf response to weaning and separation, compared with calves reared with whole-day dam-calf contact and an artificially reared, group-housed control with unrestricted access to milk for 20 min twice daily. Weaning off milk and separation from the dam can be viewed as 2 independent stressors. By introducing each stressor separately, it may be possible to reduce the overall behavioral response. The second aim of the present study was to investigate the effect of 1-wk fence-line weaning before permanent separation. The study was conducted with a 3 × 2 factorial design with dam contact treatments (whole-day, half-day, and control) and weaning treatments (simultaneous, and stepwise). Whole-day calves were separated twice daily from their dams during milking, whereas half-day calves were separated daily from the afternoon milking and until next morning milking. Simultaneous weaning and separation were done in wk 9, and stepwise weaning and separation started in wk 8 with calves being fence-line weaned before permanent separation in wk 9. Data were collected on 69 dairy calves in wk 8 and wk 9, and data were summarized over the 2 weeks for analysis. Stepwise weaning and separation reduced the number of high-pitched vocalizations and activity of dam-reared dairy calves but had little effect on control calves. There was no difference between whole-day and half-day calves in their response to separation, but as expected, dam-reared calves reacted more strongly than the control group. This was also reflected in the average daily BW gain the week after weaning, with control calves having higher average daily gains than whole-day, while half-day calves were intermediate. However, the behavioral response did not fully wane within the observation period (0-48 h of interventions). In conclusion, 1-wk fence-line weaning reduced the summed weaning and separation response in dam-reared calves. However, no difference between half-day dam-calf contact and whole-day dam contact was detected in the behavioral response to weaning and separation.
让大坝养育小牛是一种替代的做法，在奶牛养殖中，奶牛和小牛可能会从自然和高度激励的行为中获得福利益处。然而，这种制度与增加分离和断奶反应有关。减少母犊每日接触时间可能是为断奶和分离做准备的一种方式。本研究的第一个目的是研究与每天与母犊接触的小牛相比，8 周的半天母犊接触对小牛断奶和分离反应的影响，对照组小牛则每天与母犊接触，同时每天接受 20 分钟的人工饲养，并且每天两次自由接触牛奶。断奶和与母畜分离可以被视为 2 个独立的应激源。通过分别引入每个应激源，可能会减少整体行为反应。本研究的第二个目的是研究 1 周围栏断奶对永久分离前的影响。该研究采用 3×2 因子设计，母畜接触处理（全天、半天和对照组）和断奶处理（同时和逐步）。全天组的小牛在挤奶期间每天与母畜分离两次，而半天组的小牛每天从下午挤奶开始与母畜分离，直到第二天早上挤奶。同时断奶和分离在第 9 周进行，逐步断奶和分离在第 8 周开始，第 9 周围栏断奶，第 9 周进行永久断奶。第 8 周和第 9 周共采集了 69 头奶牛的数据，分析时汇总了 2 周的数据。逐步断奶和分离减少了高音调叫声的数量和哺乳期奶牛的活动，但对对照组小牛几乎没有影响。全天和半天组小牛对分离的反应没有差异，但正如预期的那样，哺乳期小牛的反应比对照组更强。这也反映在断奶后一周的平均日增重上，对照组小牛的平均日增重高于全天组，而半天组则介于两者之间。然而，行为反应并没有在观察期（干预后 0-48 小时）内完全消失。总之，1 周围栏断奶减少了哺乳期小牛的总和断奶和分离反应。然而，在断奶和分离对小牛的行为反应方面，半天母犊接触与全天母犊接触之间没有差异。
