ABSTRACT
Through daily inspection of feces and urine, the stallion detects mares in heat via olfactory signals (pheromones) (25). He is, however, not capable of detecting whether the mare is at the peak of the heat cycle, at the beginning, or already at the end. To test this, he starts with mating foreplay. He grazes close to the mare, makes frequent nasonasal contact, courts her with a collected gait and a bent neck, engages in frequent grooming with her, and sniffs and nibbles at her flanks, rear legs, and the anogenital region (26). He will often extend his penis and sometimes he will try to mount her. Early in the heat cycle copulation generally does not take place because the mare will try to avoid the stallion (27) by passively moving forward or by actively kicking at him, the latter of which is frequently accompanied by squealing and urine squirting. In this case, the experienced stallion will retreat so that, under natural conditions, injuries are the exception.
