Neigh-bours: Why every young horse needs good friends. A pilot study during the breaking-in period

In natural conditions, horses (Equus caballus) are social animals that live in stable groups. However, horses are often housed in individual stalls from the moment they begin their initial training, also called breaking-in. Individual stabling induces social isolation and confinement, and is a source of particularly stressful events for the young horse alongside the breaking-in process. These experiences can lead to behavioural disorders in individual stalls and dangerous defensive behaviours in human-horse interactions. This study aimed to evaluate how the maintenance of social contacts impacts the behaviour of young horses during breaking-in. The comparison involved 12 young horses all housed in individual stalls for one month: six individuals had the opportunity to interact socially in pairs for two hours a day (hereafter called “Social Condition”) in a “social box”, and six individuals had no access to a social partner (hereafter called “Isolated Condition”). We collected data for various behavioural variables during training sessions (body tension, conflict behaviours, cooperation and ear positions used as an indicator of the emotional state) and activities in the individual stalls. We found that horses in the Social Condition expressed fewer abnormal behaviours (p