Researchers from the University of Kentucky (UK) Gluck Equine Research Center recently investigated two ways to help advance the breeding season in mares: using recombinant follicle stimulating hormones and by using mobile light therapy.

Using Recombinant Follicle Stimulating Hormone

Gluck Center researchers recently studied the use of recombinant hormones to induce reproductive cyclicity and advance the breeding season in mares. The study, done in collaboration with the University of California and Colorado State University, was to determine the efficacy of an equine recombinant follicle stimulating hormone (reFSH) in noncycling mares housed under natural light conditions.

The transition from reproductive inactivity during the winter to the breeding season can be a lengthy and complicated process. Increased daylight suppresses melatonin (a natural hormone that prevents a mare from cycling in the winter) and allows secretion of reproductive hormones that are necessary to induce ovulation and reproductive cycles. Mares under natural light do not enter the breeding season until late April. The onset of the transition period is characterized by an increase in follicle development and uterine edema