Familiarity influences social networks in dairy cows after regrouping
Familiarity influences social networks in dairy cows after regrouping
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DOI：
10.3168/jds.2020-18896
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发表时间：
2021-03-03
影响因子：
3.5
通讯作者：
Melzer, N.
中科院分区：
文献类型：
--
作者：
Foris, B.;Haas, H-G;Melzer, N.
在管理奶牛群时，重组是一种常见的做法，众所周知，它对行为和生产具有破坏性影响。在重新组合时，一小群熟悉的奶牛的存在可能提供社会支持并减轻一些负面影响。在本研究中，我们调查了(1)重组如何影响熟悉的奶牛之间的社会关系；(2)重组后奶牛是否更喜欢熟悉的个体而不是不熟悉的个体作为社会伙伴。我们使用3组奶牛创建了2个新组，每个组包含14头奶牛，使用原组中熟悉动物的子组（即4头，6头和4头奶牛）。新组在奶牛的年龄、胎次和父系方面是相似的。通过观察重组前48 h、重组后直接和1周后的连续视频，确定步行街、卧栏和饲料铺的梳理和移位频率。首先，采用社会网络分析的方法研究了重组对熟悉奶牛亚群内关系的影响。其次，我们确定熟悉的奶牛在重组后是否比预期的偶然（即分类）更紧密或更少地联系在一起，考虑位移、梳理和饲料铺邻居网络（来自电子喂食器数据）。重新组合增加了位移的数量，特别是在步行街。在熟悉的奶牛的亚群中，重新分组导致了稍微多的位移，但网络结构没有改变。在所有观察期间，熟悉的奶牛梳理毛发的频率保持稳定，网络结构不受重组的影响。我们发现在梳理和饲料铺邻居网络中存在正分类，从而表明奶牛在重组后直接选择熟悉的个体作为梳理伙伴和喂养邻居，并且在较小程度上，在1周后。熟悉度对位移的影响取决于笔的面积。在饲料铺重新组合后直接进行的弱分类表明，熟悉的奶牛比不熟悉的奶牛更容易相互取代，可能是因为它们更经常是邻居。我们的研究结果表明，一小群熟悉的奶牛可能在重组后提供持续的社会缓冲。需要对多个群体和更大的群体规模进行进一步的研究，以确定当熟悉的奶牛群体受到重组时，是否会持续出现类似的效果。
Regrouping is common practice when managing dairy cow groups, and it is known to have disruptive effects on behavior and production. The presence of a small group of familiar cows upon regrouping may provide social support and mitigate some of the negative effects. In this study we investigated (1) how regrouping affects social relationships among familiar cows and (2) if cows prefer familiar individuals over unfamiliar ones as social partners after regrouping. We used 3 established groups of cows to create 2 new groups, each containing 14 cows, using subgroups of familiar animals (i.e., 4, 6, and 4 cows) from the original groups. The new groups were similar in respect to the age, parity, and sire of cows. The frequencies of grooming and displacements were determined in the walking alley, lying stalls, and feed bunk by observing 48 h of continuous video before regrouping, directly after regrouping, and 1 wk later. First, social network analysis was applied to investigate the effects of regrouping on the relationships within the subgroups of familiar cows. Second, we determined if familiar cows were more or less connected than would be expected by chance (i.e., assortment), considering displacement, grooming, and feed bunk neighbor networks (derived from electronic feeder data) after regrouping. Regrouping increased the number of displacements, especially in the walking alley. Within the subgroups of familiar cows, regrouping resulted in slightly more displacements, but the network structure did not change. The frequency of grooming among familiar cows remained stable across all observation periods, and the network structure was not affected by regrouping. We found positive assortment in grooming and feed bunk neighbor networks, thereby suggesting that cows preferred familiar individuals as grooming partners and feeding neighbors directly after regrouping and, to a smaller extent, 1 wk later. The effect of familiarity on displacements depended on the pen area. The weak assortment directly after regrouping at the feed bunk indicated that familiar cows displaced each other more than unfamiliar ones, possibly because they were neighbors more often. Our results indicated that a small group of familiar cows may provide ongoing social buffering after regrouping. Further research with multiple groups and larger group sizes is needed to determine whether similar effects are consistently present when groups of familiar cows are subjected to regrouping.