Barry Ball, DVM, PhD, Dipl. ACT, Albert G. Clay endowed chair in equine reproduction and professor in the department of veterinary science at the University of Kentucky (UK) Gluck Equine Research Center, gave a talk about reproduction in the geriatric mare at the 6th Annual Kentucky Breeders’ Short Course in Lexington, Kentucky, on Jan. 24.

The older mare undergoes several uterine changes. Ball focused on pregnancy and ovarian, oviductal, and uterine factors.

Unlike humans, mares do not undergo menopause, although their eggs do deplete eventually. Ball emphasized that the actual age and reproductive age of a mare are not the same. The reproductive age is dependent on the number of oocytes (eggs) populated in the mare’s ovary at birth. Therefore, fertility decreases as the antral follicle count, or ovarian reserve, diminishes. Ovarian senescence refers to an ovary with no antral follicles or a depleted ovarian reserve.

According to Ball, there will eventually be a marker to determine the reproductive age of older mares. This would benefit the equine industry by allowing individuals to predict how fast the mare will age reproductively