Breeding the aging mare
Some of the best broodmares are those who have a long history of breeding. If you have an older mare from whom you are hoping to get at least one more foal out of before retirement, it is important to consider how her age affects her breeding capabilities.
Fertility typically begins to decline around 15 years of age so you should be prepared to encounter some challenges while breeding an older mare. Mares who have been consistently bred have a higher chance of getting in foal again as opposed to older mares who are maidens or have had a few years off. For this reason, you should be thinking ahead about long term breeding plans.
Breeding conformation can easily be overlooked but it does impact conception rates. Older mares probably have a different body condition when compared to younger mares. With age and the increased number of pregnancies, the uterus drops further into the abdomen. Older mares may have had multiple foals or have perhaps suffered injuries causing their pelvic structure to be altered. When the space between a mares anus and vulva is not parallel, it can impede on her ability to maintain a pregnancy. This pelvic tilt not only creates a difficult access for live cover, it increases the risk of contamination of the reproductive tract by fecal matter regardless of the breeding method. This contamination can cause infections and reduce your mares chances of getting in foal, cause her to reabsorb embryos or abort a pregnancy. If this is something you have noticed in your broodmare, ask your vet if it would be appropriate to perform a procedure called a Caslick to surgically close the upper portion of the vulva.
You’ve got your mare in foal but that's only the first hurdle, keeping older mares in foal can be a constant challenge. First of all, when breeding an older mare you should be sure she is fit to carry a pregnancy to full gestation. Lameness issues should be evaluated due to the extra weight she’ll be carrying along with body condition score and overall health. It is nothing but a waste of time and money to breed a mare who won't be able to carry a foal full term due to the demands of fetal development and the physical strain it puts on the body.
Not to mention, the act of foaling itself requires a substantial amount of strength and energy and health compromised mares are more likely to suffer from dystocia. Worst case scenario, orphaned foals can be emotionally and financially stressful on breeders. They also take up a lot of time until a plan is successfully put in place to ensure their survival. Older mares also have a higher likelihood of having developed hormonal imbalances, endometrial cysts, uterine scar tissue, experiencing post-mating inflammation and be predisposed to developing uterine infections.
If you’re breeding an older mare, it is a good idea to have your vet do a reproductive exam. This exam should include a uterine culture, anatomy assessment and an evaluation of the reproductive tract with an ultrasound to look for any of the aforementioned issues. It is also crucial to track your mares cycle since she has an increased chance of being irregular or easy to miss. When your mare is confirmed in foal, have your vet take a blood sample to make sure her hormone levels are are in the proper range to maintain her pregnancy. Luckily, the FoalPoint system is so comprehensive, you can confidently tackle breeding an older mare.
De Blanc. M. 2016 “Breeding: Fertile Conformation”. The American Quarter Horse Journal.
McCue, Patrick M. 2016. “Breeding the Older Mare.” Colorado State University.