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

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.

Keywords: driving; individual housing; social interactions; stallions; welfare.

Figure 1

Experimental procedure. The black dotted line indicate the housing system of the stallions at the time during which they were observed (before, during and after being housed in social box). The black arrows indicate the different days during which the drive tests were performed. “CB” is the abbreviation for conventional box, “SB” for social box.

Figure 2

“Total interactions during Day1”. Boxplot of the total interactions recorded in the different treatments (before, during and after being housed in social box) during the first day. The horizontal line shows the median, the box extends from the lower to the upper quartile, and the whiskers to 1.5 × the interquartile range above the upper quartile or below the lower quartile. The black dots indicate the means. Significant differences between treatment are indicated as ** p ≤ 0.001. The lines show the model estimates (middle line) and 95% confidence intervals (upper and lower line).

Figure 3

“Total interactions before being housed in social box”. Boxplot of the total interactions recorded during the different days, before being housed in the social box. The horizontal line shows the median, the box extends from the lower to the upper quartile, and the whiskers to 1.5 × the interquartile range above the upper quartile or below the lower quartile. The black dots indicate the mean. Significant differences between treatments are indicated as * p ≤ 0.05, ** p ≤ 0.001.