Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Box 7023, SE-750 07 Uppsala, Sweden.
Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark.
J Dairy Sci. 2023 Apr;106(4):2685-2699. doi: 10.3168/jds.2022-21915. Epub 2023 Feb 22.
In modern freestall barns where large groups of cows are housed together, the behavior displayed by herd mates can influence the welfare and production of other individuals. Therefore, understanding social interactions in groups of dairy cows is important to enhance herd management and optimize the outcomes of both animal health and welfare in the future. Many factors can affect the number of social contacts in a group. This study aimed to identify which characteristics of a cow are associated with the number of contacts it has with other group members in 2 different functional areas (feeding and resting area) to increase our understanding of the social behavior of dairy cows. Inside 2 herds housed in freestall barns with around 200 lactating cows each, cow positions were recorded with an ultra-wideband real-time location system collecting all cows' positions every second over 2 wk. Using the positioning data of the cows, we quantified the number of contacts between them, assuming that cows spending time in proximity to one another (within a distance of 2.5 m for at least 10 min per day) were interacting socially. We documented in which barn areas these interactions occurred and used linear mixed models to investigate if lactation stage, parity, breed, pregnancy status, estrus, udder health, and claw health affect the number of contacts. We found variation in the number of contacts a cow had between individuals in both functional areas. Cows in later lactation had more contacts in the feeding area than cows in early lactation. Furthermore, in one herd, higher parity cows had fewer contacts in the feeding area than first parity cows, and in the other herd, cows in third parity or higher had more contacts in the resting area. This study indicates that cow characteristics such as parity and days in milk are associated with the number of contacts a cow has daily to its herd mates and provides useful information for further research on social interactions of dairy cows.
在大型奶牛群体共同居住的现代自由卧床牛舍中，同群奶牛的行为表现可以影响其他个体的福利和生产。因此，了解奶牛群体中的社会互动对于加强牛群管理和优化未来动物健康和福利的结果非常重要。许多因素会影响群体中的社会接触次数。本研究旨在确定奶牛的哪些特征与其在 2 个不同功能区（采食区和休息区）与其他群体成员的接触次数有关，以增加对奶牛社会行为的理解。在 2 个饲养在自由卧床牛舍的牛群中，每个牛舍约有 200 头泌乳奶牛，使用超宽带实时定位系统记录牛的位置，每 2 周收集所有奶牛的位置信息，每秒钟记录一次。使用奶牛的定位数据，我们量化了它们之间的接触次数，假设每天至少有 10 分钟时间内奶牛之间的距离在 2.5 米以内，它们就处于社交互动中。我们记录了这些互动发生在牛舍的哪些区域，并使用线性混合模型来研究泌乳阶段、胎次、品种、妊娠状态、发情、乳房健康和蹄部健康是否会影响接触次数。我们发现，在这两个功能区中，奶牛之间的接触次数存在个体差异。泌乳后期的奶牛在采食区的接触次数多于泌乳早期的奶牛。此外，在一个牛群中，高胎次奶牛在采食区的接触次数比初产奶牛少，而在另一个牛群中，三胎及以上的奶牛在休息区的接触次数更多。本研究表明，奶牛的特征，如胎次和产奶天数，与奶牛每天与同群奶牛的接触次数有关，并为进一步研究奶牛的社会互动提供了有用的信息。
