Animal Welfare Program, Faculty of Land and Food Systems, 2357 Main Mall, University of British Columbia, Vancouver, BC, V6T 1Z6, Canada.
Animal Production Systems Group, Wageningen University and Research, PO Box 338, 6700 AH, Wageningen, The Netherlands.
Sci Rep. 2020 Aug 28;10(1):14233. doi: 10.1038/s41598-020-70927-w.
Early cow-calf separation prevents much of cows' natural maternal behaviour. Early separation is thought to prevent the development of a cow-calf bond. To assess this bond, we measured motivation of dairy cows to reunite with their calf. To vary the degree of bonding, some cows were allowed continued contact with their calf and others were separated from their calf soon after birth, following standard practice on most farms. Among cows allowed continued contact, some were able to suckle their calf and others were prevented from suckling (by covering the cow's udder with an udder net). Cows were habituated to the weighted-gate apparatus before calving by daily training with the (un-weighted) gate. After calving, cow willingness to use the gate was assessed by determining if she would push open the gate to access to her own calf. Testing occurred once daily, with weight on the gate gradually increased. After passing through the gate, the dam's calf-directed behaviour was recorded. Suckled cows pushed a greater maximum weight (45.8 ± 7.8 kg) than separated cows (21.6 ± 6.7 kg) and non-suckled cows (24.3 ± 4.5 kg), with no differences between separated and non-suckled cows. Once reunited, latency to make nose contact and duration of licking did not differ between treatments. We conclude that motivation for calf contact is greater for cows that are suckled.
早期的母子分离阻止了奶牛的许多自然母性行为。早期分离被认为会阻止牛犊与奶牛之间建立联系。为了评估这种联系,我们测量了奶牛与小牛团聚的动机。为了改变结合程度,一些奶牛被允许与小牛继续接触,而另一些奶牛在出生后不久就按照大多数农场的标准做法与小牛分离。在允许继续接触的奶牛中,一些可以哺乳小牛,而另一些则被阻止哺乳(通过用奶网覆盖奶牛的乳房)。在分娩前,奶牛通过每天用(无重量)门进行训练来适应称重门装置。分娩后,通过确定奶牛是否会推开门以接触自己的小牛来评估她使用门的意愿。每天进行一次测试,逐渐增加门上的重量。通过门后,记录了母畜的小牛指向行为。哺乳的奶牛推动的最大重量(45.8 ± 7.8 公斤)大于分离的奶牛(21.6 ± 6.7 公斤)和未哺乳的奶牛(24.3 ± 4.5 公斤),分离的奶牛和未哺乳的奶牛之间没有差异。一旦团聚,接触鼻子的潜伏期和舔舐的持续时间在处理之间没有差异。我们得出结论,哺乳的奶牛对小牛接触的动机更强。