By: Tina Lewis, Lewis Stallion Station
Most serious breeders breed their mares every year so they can get a bigger return on their investment and so that their mares can effectively “earn their keep”. Horses are officially a year old on January 1 after their birth date and must continue to use that date as their “universal” birth date. Because of this, it is optimal, in the show world, to have a foal born on January 1st. This makes for a bigger yearling, but, by the same token, it would be highly detrimental if a foal happens to be born on December 31st, as it is then considered a yearling the very next day and would be a very small yearling in the show ring. Most mare owners try to have their foals born as close to that “universal” birth date of January 1, as possible, by breeding as early in the year as possible. Having foals born early, means bigger weanlings and yearlings for showing and winning.
If a mare, for one reason or another, is due to foal late in the Spring or early Summer, some breeders will elect not to re-breed her when she foals and put her under lights over the winter to induce estrus early the next year. This way, she can be bred for a January baby the following year. In reality, this does not skip a whole year, it only loses a few months and gains the advantage in the show ring. Some breeders may also elect to skip a year and give the mare a break or rest, or to keep down the herd, as it is sometimes not cost effective to have too many mouths to feed and gives them time to break and sell the horses already on the ground, especially in a slow market for horses.
Most good broodmares will breed, take, and carry foals until they die. Choosing the time of year you want to have a foal hit the ground, especially for your area, is important when deciding when to breed your mare. If you have severe weather in the winter, you will not want a January baby unless you have an enclosed barn to keep it warm until the weather is better. If you are trying to gain a few days each year and get your mare foaling earlier in the season you will need to either skip a year and put her under lights and start early the next season or simply be diligent in breeding on the foal heat each year, thereby gaining about 10 days per year (easier said than done, at least, consistently).
It is common practice to breed a mare on her foal heat as long as there were no foaling problems, such as a retained placenta, she kept her weight well, and she is healthy. Some breeders believe that keeping that reproductive tract active helps to keep it in good working order. Catching a mare on her foal heat, is a bit tricky. Unlike the regular heat, normally 5-7 days, the foal heat generally lasts only 3 days beginning on about day 9-12 after the mare foals. The success rate for getting a mare in foal on her foal heat drops to about 50%, for several reasons.
Once the mare foals, the ovaries will begin to start cycling. Unfortunately, they start from a stage that is similar to being about half way through a normal heat cycle, so it is only about 10 days until the ovulation occurs. This can vary from 5-16 days. Getting a mare to even tease to a stallion, much less breed on her foal heat is quite a task, understandably, since it has only been 10 days since she delivered a 150 pound foal, placental tissue, and the fluids that surrounded the foal. Her uterus is contracting the muscle in the walls, and is frantically trying to evacuate itself so it can clean up any residual left behind from the birth. These contractions are strong and cause considerable discomfort. Often times a mare will pass the tenth day and not have shown any signs of heat at all by normal teasing methods, but would have had a normal follicle show on an ultrasound exam. Some mares will be physiologically in heat, but not psychologically receptive to the stallion due to the new foal and a mother’s concern for her foal’s safety in the presence of the screaming, charging, stallion.
If the mare does not show any signs of heat, but you can determine she is in standing heat via an ultrasound exam, and has a breedable follicle, artificial insemination would best be used in this case, to keep from injuring the mare, foal or stallion. If the mare is receptive to the stallion, the foal can be put into a safe foal pen, near the mare, to keep her anxiety levels down, while she is being bred via live cover. For shipped semen, it would be best to have a culture done, skip the foal heat and short cycle her with Prostaglandin and catch her when she comes into heat a few days later. You will still gain a few days but lessen the chances of having to ship again and lose more valuable time and money, since the foal heat is not ideal for conception via shipped cooled semen.
Most breeders start teasing or checking their mares about day 6 after the foal is born so as not to miss that short, 3 day heat. Once it’s gone the only recourse is to short cycle her and bring her back into heat (or wait for the next heat which usually occurs when the foal is about 30 days old). This heat should be a normal 5-7 day heat but she still may not show any signs with regular teasing methods due to motherly instincts, and the foal at her side. This is one of the main reasons that some breeders, in years past, only bred some mares, every other year. Until ultrasonography, there was no way to tell when these mares were actually in heat and some mares wouldn’t allow the stallion to breed her at all when she had a foal at her side. Some breeders would actually guess and use artificial insemination or even restrain a mare for live cover breeding at days 9 and 11, crossing their fingers that she would have semen inside her when she was ovulating a follicle. Today we have ultrasound, phantoms (dummy mares), Artificial Vaginas (AV’s) and Artificial Insemination (AI) to help us overcome some of the obstacles that caused so much stress to breeders over the years. We can now deal with the fears of a new mother and her brand new foal, never having to have her, or her foal, in the presence of the stallion. I believe this makes for a happier, less stressed mare, as well as mare owner, and probably greatly improves the conception rate on the foal heat.
