Social networks respond to a disease challenge in calves

Abstract

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.

Equine Social Behaviour: Love, War and Tolerance

“…These quantitative criteria are primarily based on the reported interindividual distance of 2 m to two horse lengths, within which horses only tolerate close affiliates [12,13,27,38,39,54,[115][116][117] and include measurements of spatial proximity between two horses, the number and duration of affiliative or agonistic interactions per hour and recording the nearest neighbour. In addition, recent studies have incorporated social network analysis to examine indirect connections beyond the dyad level and analyse the patterns of individual and group-level social interactions [41,52,[118][119][120][121].…”

“…The combination of a more nuanced qualitative assessment of equine social behaviour with quantitative approaches may greatly assist equine welfare assessment and optimization, as poor welfare conditions, such as high population density (< 331 m2 per horse), may reduce equine sociality and skew horses' social behavioural repertoire toward agonistic interactions [80,122,123]. Changes in social behaviour have also been associated with disease in various group-living species ranging from honeybees, zebrafish and mice to calves and humans [121,[124][125][126][127], but the link between social networks and health has not yet been explored for horses. The changes seem species-specific, as mice reduce social interactions, while rhesus macaques and calves increase affiliative interactions with familiar conspecifics [121,128,129].…”

“…Changes in social behaviour have also been associated with disease in various group-living species ranging from honeybees, zebrafish and mice to calves and humans [121,[124][125][126][127], but the link between social networks and health has not yet been explored for horses. The changes seem species-specific, as mice reduce social interactions, while rhesus macaques and calves increase affiliative interactions with familiar conspecifics [121,128,129]. More detailed studies in sick humans found increased social interactions with familiar support figures but withdrawal from strangers and a strong correlation between pain intensity and interpersonal distance to strangers in patients with lower back pain [121,127,130,131].…”

“…The changes seem species-specific, as mice reduce social interactions, while rhesus macaques and calves increase affiliative interactions with familiar conspecifics [121,128,129]. More detailed studies in sick humans found increased social interactions with familiar support figures but withdrawal from strangers and a strong correlation between pain intensity and interpersonal distance to strangers in patients with lower back pain [121,127,130,131]. Expanding social behavioural research in horses to also include assessment of the effect of acute and chronic disease on social interactions may further advance equine welfare by facilitating early detection, treatment and monitoring of disease and pain.…”

Clinical examination of cattle. Part 2: calves, technology and ancillary testing

“…Calves that are showing signs of disease are often dull and depressed, lying away from the rest of the group and appear less inquisitive. It has been shown that before a disease incidence, calves alter their behaviour, reducing the amount of play behaviour and social interactions with the calves around them (Burke and others 2022). On approaching the pen, calves should respond by either moving away from the observers, or curiously moving closer to them.…”