Vet Ed Lyall looks at what makes the perfect broodmare and advises on avoiding common breeding pitfalls.
There are many different criteria people use when selecting a broodmare. Sometimes it’s because she’s a treasured family member and the owner wants to have a foal as a bit of fun and to keep to ride, but usually it’s because the mare has been successful in her sport and there’s a desire to replicate or improve on her performance in her offspring by selecting a highly rated stallion.
Now, with the advent of embryo transfer mares don’t have to wait until their sporting career is over to start producing offspring: they can remain in work and competition and a surrogate mare can carry the foal.
Making your selection
Most mares are selected for their own or their previous offspring’s performance records in whatever discipline they compete. When selecting mares to breed from, it’s important to try to avoid using those with inheritable defects. If the mare is good enough, there are other inheritable problems that might have to be ignored, for example, a parrot mouth. This defect seems to be strongly inherited, but it would be difficult for any vet to advise not breeding from a mare who has a parrot mouth but the talent to complete a four-star horse trials. There are several inherited traits we usually see mares passing on to their foals. These include umbilical or inguinal hernias, however, as with the parrot mouth, modern veterinary medicine means we can deal with these problems when they arise.
Conformation is always a huge factor in broodmare selection. Points such as good feet and the correct hock angles, as well the correct length of neck and back, are important to look out for. However, if there are subtle issues, choosing a stallion that is an excellent example of the required conformation or is known to throw foals with the desired attributes is always the best idea.
The importance of temperament
Temperament should also be thought about, as there’s no point breeding from a mare that is difficult or impossible to handle or throws unrideable foals. Again, poor temperament may possibly be counteracted by choosing a stallion of good temperament.
Mares can be put in foal from the age of two and I usually advise waiting at least until the mare reaches her second birthday before starting. However, if she’s physically immature it’s best not to breed from her in the two-year-old year.
If a mare is to be broken and then ridden for high-level sport it might not be advisable to put her in foal young as the pelvic ligaments, which relax to allow the birth of the foal, may end up too slack after foaling to help her reach her highest level of performance.
Fertility and age
Mare fertility starts to drop after the mid-teens. Often, we find older mares have conditions such as a tight cervix, which can cause problems with obtaining a pregnancy. However, due to modern reproductive medicine most age-related problems can be managed, other than the fact that the mare’s eggs are of lower quality as she ages and this can affect fertility. Having said this, I have managed to get many maiden mares aged over 20 in foal successfully. There is, however, the concern that the older mare’s foals are sometimes physically smaller and weaker than those produced by her younger counterparts.
To sum up, in an ideal world, the mare you select for breeding will be free of inheritable defects, have perfect conformation and a good temperament. She will also have a performance record that justifies her use as a broodmare and will be of an age that is appropriate for breeding.