Unexpected correlates of stereotypic behaviour in domestic horses
Résumé
In domestic horses, many aspects of stereotypic behavior are still under question.
Social, housing and feeding conditions, as well as genetic predispositions, seem
to be involved – but little is still known about the determinants of the type of
stereotypy performed, nor about the potential correlates of such behaviours with
reproduction, cognitive abilities or working conditions. These issues will be
addressed here via two complementary studies, one on breeding mares, the other
on working horses, both involving large samples of animals living in the same
conditions and with limited genetic variability (one breed in each case). These
studies reveal 1) a clear relation between reproductive success and the
occurrence of stereotypies (lower conception rates in stereotypic mares), and a
relation between reproductive status (barren, maiden or with foal) and the
occurrence and type of stereotypies; 2) relations between cognitive performance
and stereotypies (lower learning in stereotypic horses), and between the type of
work usually performed and the occurrence and types of stereotypies performed
when animals were stabled. The types of stereotypies observed also differed
greatly between these two studies. These datasets raise further lines of
discussion on the physiological, emotional and motor correlates of these
abnormal behaviours.