Weaned horses, especially females, still prefer their dam after five months of separation

Under natural conditions, foals stop nursing from their dam at approximately-9 months old, but their bond persists until 1.5-2.5 years of age. In contrast, in horse breeding, foals are generally artificially weaned and totally separated from their dam at 5-7 months. However, it is not known whether the bond between the dam and her foal is maintained after artificial weaning. The aim of this study was (1) to assess whether foals still recognise and prefer their dam over other familiar mares several months after weaning and (2) to evaluate whether the preference for the dam is more pronounced in fillies or colts. Fifteen fillies and 19 colts were weaned at the age of 7 months old (complete separation from the mother). At the age of one year (i.e., 5 months after the separation), they underwent a test evaluating their preference for their dam or a familiar mare from their natal group. Significantly more foals first approached their dam; they also sniffed and tended to look more often at her. This finding indicates that artificially weaned horses remember and still exhibit a preference for their dam, suggesting that the bond persists even after 5 months of separation. Moreover, fillies exhibited a stronger preference for both mares than colts: they looked at them more frequently, sniffed them for a longer duration and spent more time in proximity to both mares than colts. This suggests that fillies generally have an even stronger attachment to their dam as well as to other mares from their natal group. This study calls into question the practice of artificial weaning at 5-7 months of age.