Effect of hCG and prostaglandin on ovarian, luteal development, and hormonal changes in embryo donor mares during the hot summer months in subtropics.

Background: Commercial embryo flushing of horses has required hormonal management of both the donor and recipient mares throughout the breeding season.

Aim: This study aimed to find out the effect of using human chorionic gonadotropin (hCG) and prostaglandin F2α (PG) on the ovarian and uterine dynamics and hemodynamics, estradiol (E2), progesterone, oxidants-antioxidants, and blood biochemicals in embryo donor mares during the hottest months of the year in a subtropical climate.

Methods: Three Control estrous cycles of native mares (10-20 years; = 10) followed by two treated cycles with hCG and PGF2α were examined daily from May to August using Doppler ultrasound with blood sampling.