ABSTRACT
Most reproductive physiologists define the complete cycle as the amount of time (days) from the first day of heat until the first day of the next heat period. Diestrus is that portion of the estrous cycle in which the mare is not in heat. After the horseman has a working knowledge of the estrous cycle, he can determine a mare's condition in relationship to the cycle. This can be done by rectal palpation and the use of a teaser stallion. Good records are a must in horse breeding; they are necessary in managing the mares so that as many as possible are in foal. Mares can be teased by leading the stallion in front of their stalls and paddocks or by placing the stallion in a small pen in the center of a paddock full of mares. Some not-so-scientific suggestions that may help the breeding business include prevention of practices such as hauling the mare immediately after foaling.
