Monk Jessica E, Hine Brad C, Colditz Ian G, Lee Caroline
CSIRO Agriculture and Food, FD McMaster Laboratory Chiswick, Armidale, NSW 2350, Australia.
School of Environmental and Rural Science, University of New England, Armidale, NSW 2350, Australia.
Animals (Basel). 2018 Apr 3;8(4):51. doi: 10.3390/ani8040051.
The speed with which animals acclimate to a new environment could be an important measure of ability to cope with management induced stress. This study developed a measure of acclimation rate in a group of 50 heifers during yard weaning over nine days. We recorded the time and order in which heifers moved through a novel funnel structure into a feeding yard daily. We hypothesised that addition of an obstacle at the entrance would increase the time it took heifers to move through the funnel, but that they would acclimate to the obstacle over a three-day period. The change in latency to move through could then be used as a measure of acclimation rate. We hypothesised that individuals which acclimated to obstacles at a faster rate might display favourable temperament as assessed by flight time. All heifers took longer to move through the funnel after a novel object was introduced, then latency decreased over the following two days while the object was present. This indicates the protocol could be useful for measuring acclimation rate at a group level. Individual acclimation rate variables, measured as change in times and orders of heifers between test days, did not appear to have any consistent relationships with flight time or weight change during or post-weaning ( > 0.05). We concluded that the protocol was inappropriate for assessing acclimation rate at an individual level, due to social effects while testing heifers as a group. Heifers which were consistently one of the first 20 to move through the funnel had a significantly greater average weight 5 and 10 months post-weaning (345 ± 9 kg and 518 ± 10 kg respectively) than heifers which were consistently one of the last 20 through the funnel (311 ± 8 kg and 484 ± 8 kg respectively; < 0.001). This may indicate order of movement through the funnel was related to feeding motivation or another aspect of temperament not reflected by flight time.
动物适应新环境的速度可能是应对管理诱导应激能力的一项重要指标。本研究针对50头小母牛在为期九天的围栏断奶期间，制定了一种适应率的测量方法。我们记录了小母牛每天通过一个新型漏斗结构进入饲养场的时间和顺序。我们假设在入口处添加障碍物会增加小母牛通过漏斗的时间，但它们会在三天内适应该障碍物。然后，通过漏斗所需时间的变化可作为适应率的一项指标。我们假设，那些能更快适应障碍物的个体，经飞行时间评估可能表现出良好的性情。引入一个新物体后，所有小母牛通过漏斗的时间都变长了，然后在接下来的两天里，当物体存在时，所需时间减少。这表明该方案可用于在群体层面测量适应率。以小母牛在测试日之间时间和顺序的变化来衡量的个体适应率变量，似乎与断奶期间或断奶后（P>0.05）的飞行时间或体重变化没有任何一致的关系。我们得出结论，由于在对小母牛进行群体测试时有社会影响，该方案不适用于在个体层面评估适应率。始终是最早20头通过漏斗的小母牛，在断奶后5个月和10个月的平均体重（分别为345±9千克和518±10千克）显著高于始终是最后20头通过漏斗的小母牛（分别为311±8千克和484±8千克；P<0.001）。这可能表明通过漏斗的顺序与采食动机或飞行时间未反映的性情的其他方面有关。
