Wegner C S, Rönnegård L, Agenäs S, Eriksson H K
Department of Applied Animal Science and Welfare, Swedish University of Agricultural Sciences, Box 7024, 750 07 Uppsala, Sweden.
Department of Animal Biosciences, Swedish University of Agricultural Sciences, Box 7023, 750 07 Uppsala, Sweden; School of Information and Engineering, Dalarna University, 791 88 Falun, Sweden; The Beijer Laboratory for Animal Science, Swedish University of Agricultural Sciences, Box 7024, 750 07 Uppsala, Sweden.
Animal. 2025 Jun;19(6):101525. doi: 10.1016/j.animal.2025.101525. Epub 2025 Apr 22.
Cow-calf contact (CCC) systems, where cows and calves are housed together during all or part of the milk-feeding period, foster strong social bonds within dam-calf pairs. However, calves are still generally weaned and separated at younger ages than have been observed for semi-feral cattle. This study aimed to evaluate behavioural responses of dairy cows and calves to fenceline weaning after 4 or 6 months of full CCC. Additionally, the proportion of time spent by dam-calf pairs in close proximity (< 4 m indoors or < 8 m outdoors) prior to weaning was tested for its effect on behavioural responses. Dairy cows (n = 25) and their calves (n = 26) were housed in a freestall pen with free access to pasture for either 4 (4MO) or 6 months (6MO), after which calves were weaned outdoors via fenceline separation. Daily activity (lying time and step count) was recorded for all animals using accelerometers for 6 days before and for 11 days after weaning, while vocalisations and feed-seeking behaviour were collected for calves postweaning through direct observations. Scan sampling on 3 days during the end of the contact period was used to estimate proximity within each dam-calf pair, and calves were weighed regularly throughout the study. Calf feed-seeking behaviour and differences in lying time or step count (calculated as changes from a preweaning baseline value) for cows and calves were fitted with polynomial regression models. Directly after weaning, calves responded by decreasing their lying time, increasing their step count and vocalisations, and spending little time on feed-seeking; these responses were greater for 4MO calves. The calves, especially those weaned at 4 months, had reduced growth rates for several weeks postweaning, suggesting a lack of nutritional independence prior to weaning. Cow activity responses were similar but with no clear treatment differences in the first 3 days and with faster recovery times than for calves. Dam-calf proximity varied greatly between pairs but did not influence any of the modelled responses. Our results suggest that fenceline weaning causes behavioural responses indicative of distress in both calves and (to a lesser extent) cows, even when calves are weaned at a higher age.
母牛-犊牛接触（CCC）系统是指在全部或部分哺乳期间将母牛和犊牛饲养在一起，这种系统能促进母牛与犊牛之间形成紧密的社会联系。然而，与半野生牛相比，犊牛通常仍在较小的年龄就被断奶并分开。本研究旨在评估在完全CCC饲养4或6个月后，奶牛和犊牛对围栏断奶的行为反应。此外，还测试了断奶前母牛-犊牛对近距离接触（室内<4米或室外<8米）的时间比例对行为反应的影响。将25头奶牛及其26头犊牛饲养在一个自由栏舍中，自由进入牧场4个月（4MO）或6个月（6MO），之后通过围栏分隔在室外对犊牛进行断奶。在断奶前6天和断奶后11天，使用加速度计记录所有动物的日常活动（躺卧时间和步数），断奶后通过直接观察收集犊牛的叫声和觅食行为。在接触期结束时的3天内进行扫描抽样，以估计每对母牛-犊牛之间的接近程度，并在整个研究过程中定期称量犊牛体重。犊牛的觅食行为以及奶牛和犊牛躺卧时间或步数的差异（计算为断奶前基线值的变化）采用多项式回归模型进行拟合。断奶后，犊牛立即通过减少躺卧时间、增加步数和叫声，并减少觅食时间来做出反应；4MO犊牛的这些反应更为强烈。犊牛，尤其是4个月断奶的犊牛，在断奶后的几周内生长速度下降，这表明断奶前缺乏营养独立性。母牛的活动反应相似，但在最初3天没有明显的处理差异，且恢复时间比犊牛更快。母牛-犊牛的接近程度在不同对之间差异很大，但不影响任何模拟反应。我们的结果表明，即使犊牛在较高年龄断奶，围栏断奶也会导致犊牛和（程度较轻的）母牛出现表明痛苦的行为反应。
