📒 This work describes the hormonal changes in thoroughbred mares during her reproductive cycle. It presents three trials to control the length of the estrous cycle and induce supernumerary follicles in pony and mixed bred mares. The work is directed to workers in the equine industry, veterinarians and veterinary scholars interested in equine reproduction. It serves as a reference guide for equine practitioners to induce ovulation in mares as well.