Department of Animal Sciences, University of Florida, Gainesville, FL, 32611, USA.
Sci Rep. 2022 Jun 1;12(1):9119. doi: 10.1038/s41598-022-13088-2.
Changes in network position and behavioral interactions have been linked with infectious disease in social animals. Here, we investigate the effects of an experimental disease challenge on social network centrality of group-housed Holstein bull dairy calves. Within group-housed pens (6/group) calves were randomly assigned to either a previously developed challenge model, involving inoculation with Mannheimia haemolytia (n = 12 calves; 3 calves/group) or a control involving only saline (n = 12 calves; 3 calves/group). Continuous behavioral data were recorded from video on pre-treatment baseline day and for 24 h following inoculation to describe social lying frequency and duration and all active social contact between calves. Mixed-model analysis revealed that changes in network position were related to the challenge. Compared to controls, challenged calves had reduced centrality and connectedness, baseline to challenge day. On challenge day, challenged calves were less central in the directed social contact networks (lower degree, strength and eigenvector centrality), and initiated contact (higher out-degree) with more penmates, compared to healthy calves. This finding suggests that giving rather than receiving affiliative social contact may be more beneficial for challenged calves. This is the first study demonstrating that changes in social network position coincide with an experimental challenge of a respiratory pathogen in calves.
网络位置和行为互动的变化与社交动物的传染病有关。在这里，我们研究了实验性疾病挑战对群体饲养荷斯坦奶牛犊牛社交网络中心性的影响。在群体饲养的畜栏（每组 6 只）中，犊牛被随机分配到先前开发的挑战模型中，涉及接种曼海姆氏菌（n=12 只犊牛；每组 3 只犊牛）或仅使用生理盐水的对照（n=12 只犊牛；每组 3 只犊牛）。在接种前的基线日和接种后 24 小时内，从视频中连续记录行为数据，以描述犊牛的社会躺卧频率和持续时间以及所有活跃的社交接触。混合模型分析表明，网络位置的变化与挑战有关。与对照组相比，挑战组的犊牛在基线到挑战日期间的中心度和连通性降低。在挑战日，与健康的犊牛相比，受挑战的犊牛在定向社交接触网络中的中心度较低（较低的度数、强度和特征向量中心度），并且与更多的同圈伙伴发起接触（更高的出度）。这一发现表明，给予而不是接受亲和性的社交接触可能对受挑战的犊牛更有益。这是第一项证明社交网络位置变化与犊牛呼吸道病原体实验性挑战一致的研究。
