Breeding horses can be a tricky business. A fertile mare can save a breeder a lot of time and money. Lets look at some things we can do to evaluate our mares fertility and optimize our breeding success.

Physical condition and age can play a big part in reproduction. Mares that are to thin or that are excessively over weight are often difficult to get in foal. Rectifying these conditions prior to breeding will increase your success rate. The optimal age group for easy breeding in mares is 4 to 12 yrs. This doesn’t mean that you can’t get an older mare in foal. Just realize it may take more effort to get her bred.

Reproductive conformation can play a part in breeding success. Mares that have vulva’s that are angled significantly off vertical (tipped) are more likely to have problems getting and/or maintaining a pregnancy.

Uterine Health can be evaluated by ultrasound, cytology, culture, biopsy, and other lab tests. Unless the mare has a history of reproductive problems or fails to get in foal after breeding one or two cycles I usually will rely on ultrasound for uterine evaluation.

Time of year can affect breeding. Most mares normally cycle from April to Oct. Breeders often want foals that are born earlier in the year. This can done but it often requires putting them under lights for 60 days prior to breeding. Planning ahead and preparing your mare for breeding season can hopefully make breeding your mare a positive experience. Good Luck!!

David L. Moss DVM