what are stallions used for
teaser stallion. stallion used to detect those mares which are in estrus. During the breeding season those mares to be bred are brought into a crush and the teaser brought alongside. The mares that show estral signs are kept back, usually palpated per rectum to determine the state of their ovaries, and may be bred.
(The term stallion for an uncastrated male horse dates from this time; stallion = stalled one.) Stallion is also used to refer to males of other equids, including zebras and donkeys.