Colorado State University’s Ed Squires, PhD, an honorary Diplomate in the American College of Theriogenology (reproduction), presented several lectures at the 2003 American Association of Equine Practitioners convention. One presentation was on using a new commercially available product called equine follicle-stimulating hormone (eFSH, from Bioniche Animal Health) to have mares superovulate (ovulate more than one follicle at a time).

There are three major reasons to attempt to have a mare superovulate. First, in embryo transfer programs there is a greater chance of recovering an embryo and thus reducing the expense of getting a viable embryo for transplanting. Second, superovulation of a mare in transition (early in the year before she is cycling regularly) will often hasten the onset of normal estrous cycles. Third, it can increase the chances of conception when breeding mares to sub-fertile stallions.

Studies have shown it takes about seven days for the twice-a-day eFSH injections to produce several follicles 35 mm or larger using a specific treatment protocol. Squires said the cost is about $400-$500 per cycle for the drug.

Squires said, “eFSH is a tool that can be used by the practitioner, but it might take several years for researchers and practitioners to fine-tune the protocol for eFSH.” (For more information see article #4863 online