Social Box: Influence of a New Housing System on the Social Interactions of Stallions When Driven in Pairs

SIMPLE SUMMARY: In order to improve the housing conditions of stallions in individual boxes, we tested a so-called “social box” allowing increased physical contact between neighbouring horses. This study aimed at investigating whether housing stallions in social boxes potentially changes their behaviour during carriage driving. We hypothesised that the stay in social boxes would decrease the number of unwanted social interactions when driven in pairs. Eight Franches-Montagnes breeding stallions were observed when driven in pairs with a “neutral” stallion housed in a so-called “conventional box”, strongly limiting physical contact. They were driven on a standardised route over the course of four days before, during, and after being housed in a social box. The behaviours of the pairs and the interventions of the groom and the driver during the test drives were assessed live and using video recordings. The results showed that the stallions performed more social interactions during the driving test before being housed in social boxes and that these interactions decreased over the four days. This suggests that being housed in social boxes decreased the social behaviour of stallions while driven in pairs. Another important factor in reducing unwanted social interactions of stallions during carriage driving appears to be the consistency of the driver and the groom in their demands to teach the stallions that social interactions are unwanted while being driven in pairs. Other effects, such as habituation to the test conditions and the pairing, could not be assessed here and represent a limitation of our study. ABSTRACT: In order to improve the housing conditions of stallions in individual boxes, we tested a so-called “social box” allowing increased physical contact between neighbouring horses. This study investigated whether housing stallions in social boxes changes the number of social interactions during carriage driving. We hypothesised that the stay in social boxes would decrease the number of unwanted social interactions between stallions when driven in pairs. Eight Franches-Montagnes breeding stallions were observed when driven in pairs with a “neutral” stallion housed in a so-called “conventional box”, strongly limiting physical contact. They were driven on a standardised route over the course of four days before, during, and after being housed in social boxes. The type and frequency of behaviours of the pairs and the interventions of the groom and the driver during the test drives were assessed live and using video recordings. Results from linear mixed-effect models show that unwanted social interactions decreased during and after the stallions were housed in the social box (p < 0.001). Stallions’ interactions also decreased over the four days (p < 0.01), suggesting a habituation to the test conditions by learning not to interact, or by subtly settling dominance. The social box tended to decrease unwanted social behaviours of stallions driven in pairs and could therefore be used as an environmental enrichment for horses.