In vivo Embryo Production During Induced Aluteal Cycles in the Mare

A proof of concept experiment was designed to investigate the feasibility of generating equine embryos during aluteal cycles induced by antiluteogenic treatments administered shortly after ovulation. Four cyclic mares with a median age of 9.5 years (range 9 to 16) were utilized. Mares were monitored until a preovulatory follicle 35 mm was detected on the ovary in the presence of uterine edema as determined by ultrasonography. A fertile stallion was used for artificial insemination with each breeding dose comprised of 1 x 109 total motile sperm. Mares were artificially inseminated and human chorionic gonadotropin (hCG; 2000 IU, IV; Chorulon, Merck Animal Health, Kenilworth, NJ) administered. Blood was collected every other day until ovulation was detected by twice daily ultrasonography ...