Training young horses to social separation: effect of a companion horse on training efficiency

The intensity with which a horse responds to separation from its group and subsequently to being alone is relevant for both horse and handler safety. Identification of training methods that may reduce responses to separation would be useful in practice.

To investigate whether the initial presence of a familiar companion horse modifies responses to separation from the group, lowers stress levels (as measured by heart rate) and increases training efficiency.

Habituation to separation proceeds more quickly if the horse is first trained with a companion, and heart rate is lower when the horse is subsequently trained alone, compared to control horses trained individually from the start.

Young mares (n = 32), kept in groups of 4 were exposed to social separation: 2 horses of the group were trained singly (S1, n = 16) and the remaining 2 horses (n = 16) were trained first with a companion (P2) and then alone (P1). The training comprised 3 steps whereby distance from the group was gradually increased. The final learning criterion was met when a horse fed calmly alone inside a test arena (Step 3). Horses that were trained in a pair had to succeed in Step 3 together before they repeated the steps alone. Feeding behaviour and heart rate were recorded.

There were no significant differences between S1 and P1 horses, indicating that the initial pair-training did not reduce responses in P1 horses. However, heart rate was significantly lower when horses were trained in pairs (P2) compared to when the same horses were subsequently trained alone (P1).

It may not be efficient to habituate naïve young horses to social separation initially with a partner as these horses appear to have to relearn being in the test situation alone when switching to the individual training.