The difference in the locomotor activity of horses during solitary and paired release

The objective of the study was to determine the difference in the locomotor activity of horses that are maintained with conspecifics and released into a paddock with a companion or alone. Three horses out of eleven adult Hucul geldings in the facility which were housed in pairs in box-stalls and released outdoor together were randomly included in the study. Each horse studied stayed in the box-stall with another horse which was not included in the study. Horses were released into the experimental paddock for 1 h daily over 12 days for the investigation. One solitary horse followed by one pair of horses were observed every day. The locomotor activity was quantified as the number of steps in walking, trotting or cantering and the number of changes in gait from a slower gait to a faster gait and conversely, from a faster gait to a slower gait. The influence of the treatment effect was estimated with the non-parametric Wilcoxon signed-rank test. The non-parametric Friedman test was used to estimate the day effect. The results show that the mean number of forelimb steps in trot and canter and changes in the gait were higher during paired release than in solitary release. The tendency for a higher number of steps in walk during paired release was insignificant. The Friedman test did not reveal any significant differences between the successive days. The lower locomotor activity in horses turned out alone compared to solitary release indicates that the companion provokes the other horse’s locomotion, even when the horses are maintained with conspecifics for the whole day. Considering the benefits of movement, paired turnout may be one of the factors which provide appropriate welfare for horses. This finding has implications for optimising the turnout circumstances. When voluntary exercise is desired, the horse should not be released alone. The issue warrants further investigation in horses maintained without conspecific company.