Social networks respond to a disease challenge in calves.

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.

Effects of Social Housing on Dairy Calf Social Bonding.

Social housing for dairy calves has a range of benefits for social development, yet there is limited understanding of how social bonds form early in life. We characterized effects of early life social contact on the development of social preference for calves varying in familiarity. A total of 40 calves were tested in a social preference test at 4 weeks of age to assess the formation of social bonds and preference for their peers. Within an open-field social preference test, focal calves were presented with two stimulus calves, one 'more familiar' and one 'less familiar'. We found that pair-housed calves spent more time in close proximity with either stimulus calf and had a greater preference for their pen-mate, compared to another calf reared within visual contact. Individually housed calves exhibited no preference for calves reared within visual but not physical contact compared to calves that were completely unfamiliar. Of the calves that approached both stimulus calves, individually housed calves that approached the 'less familiar' calf first spent less time near the 'more familiar' calf, whereas behavior of pair-housed calves was not affected by the first calf approached. These results suggest that physical contact is necessary for the development of social bonds in young dairy calves, and early life social housing may support the development of normal social behavior in dairy cattle.

Emotional triggers and psychopathology associated with suicidal ideation in urban children with elevated aggressive-disruptive behavior.

8.6% suicidal ideation (SI) was found among 349 urban 6-9 year olds in the top tercile of aggressive-disruptive behavior. SI was associated with more self-reported depression, ODD, conduct problems, and ADHD symptoms (ES 0.70-0.97) and 3.5-5 times more clinically significant symptoms. Parents rated more symptoms in older children associated with SI compared to parents of similar age children without SI, including greater somatic and behavior problems in 8-9 year olds with SI. Parent ratings did not differentiate SI and non-SI in 6-7 year olds. SI frequently co-occurred with thoughts about death. Children described anger, dysphoria and interpersonal conflict as motivators/triggers for SI and worries about safety/health as motivator/triggers for thoughts about death, suggesting that problems managing emotionally challenging situations are a specific factor in initiating SI. Universal and indicated interventions for children to strengthen emotional self-regulation and behavioral control are recommended to complement the current emphasis on suicide prevention among adolescents.