Veterinarians have turned to a variety of advanced reproductive technologies to enhance mare fertility. | Photo: Kevin Thompson/The Horse

As one of the keynote speakers at the 2019 Equine Science Society Symposium, held June 3-6 in Asheville, North Carolina, Janet F. Roser, PhD, professor emeritus in the University of California, Davis, Department of Animal Science, described current technologies, as well as a new hormone therapy with the potential to make them even more effective: recombinant equine gonadotropins.

First, Roser listed ART techniques and their limitations.

1. Embryo transfer (ET), which involves removing an embryo from a donor mare and placing it in a recipient mare’s uterus to carry to term. It’s a common way breeders get foals from performance mares or mares with health problems.

“One of the problems with ET is obtaining one if not more embryos from the donor mare,” Roser said. “Whereas a single ovulating mare results in a 50% embryo recovery rate, double or triple ovulations would result in a higher recovery rate