Horse Breeding Techniques And Breeding Management Resources

Breeding horses is a complicated and challenging enterprise and not one that should be undertaken by novices. If you’re thinking about breeding horses, keep in mind the fact that there is currently a horse overpopulation in the United States that results in about 100,000 horses a year being sent to slaughter. If you’re making a choice between breeding horses and properly caring for horses that already exist, you are well advised to do the latter.

Having said that, in this article we review some basics of horse breeding techniques and provide solid equine breeding management resources for those wishing to pursue this enterprise. Read on to learn more.

Natural Service Or Artificial Insemination?

equine breeding management

Natural Service

Natural service is the most common way to breed mares. To determine when it’s time to breed a mare, you may need to use a wide variety of techniques and technology including techniques such as teasing and palpation and technology such as ultrasonography via the rectum. This technology is used to detect estrus by locating a dominant ovarian follicle. This is a follicle on the ovary that enlarges in order to release an egg to be fertilized.

Mares in estrus should be bred when a dominant follicle (30 to 35 mm) is present. If you are unable to make this determination precisely, it is also possible to breed a mare on the second or third day of estrus, repeating the process on alternating days until the mare is clearly no longer in heat.

It’s important that breeding take place before the mare ovulates. This occurs within the last two days of the estrus cycle. If you have trouble keeping track of your mare’s estrus cycle, you can induce ovulation through administration of the drug known as deslorelin.

When breeding a mare, be sure to use a tail wrap to prevent hair entering the mare’s vagina. You must also maintain clean conditions by cleansing the perineum before introducing the stallion. Rinse the stallion’s penis as well. These careful steps help prevent the risk of contamination of the reproductive tract of the mare.

Avoid injury to mare or stallion by introducing the two slowly. Keep them in adjoining stalls or paddocks with very secure fencing in between until you see that the mare is receptive to the stallion. She will indicate this by raising her tail and tucking the hind legs. Additionally, urination and eversion of the vulvar lips are signs that the mare is ready to receive the stallion.

If the mare and stallion have had a chance to become acquainted, you may not need to introduce a lot of control into the process. If you fear that they may hurt each other, you may need to use a nose twitch on the mare and keep the stallion under close control by using a securely fitted halter with the chain shank.

Once breeding is complete, the horse breeder needs to make sure to rinse the stallion’s penis to lower any chance of contamination or infection.

The upside to natural service is that it is natural and can be convenient. The downsides are many. Chances of infection for both mare and stallion are great. There is also tremendous potential for danger and injury for all concerned.

Artificial Insemination

To avoid these problems, it is also possible to use artificial insemination to impregnate a mare. To do this, an artificial vagina is used to collect semen from the stallion. There’s quite a bit of technology that goes into this technique as you will need to be able to determine the concentration of sperm in the semen sample. You also need to be able to determine whether or not the motile sperm is morphologically normal. Clearly, you will need the assistance of your veterinarian for this process.

Once a usable semen sample has been obtained, you must add a semen extender which contains an antibiotic. This helps improve the survival of the sperm. It’s important that the semen extender is the same temperature as the semen itself when the two are combined.

It is common to use a semen extender that is made of a combination of glucose and skim milk. It’s not smart to do this as a DIY project, though. Your veterinarian will need to be involved.

When artificially inseminating a mare, it is important that you use a tail wrap and thoroughly cleanse the perineum. If you use soap for this cleansing, be sure to rinse it away completely so that it will not interfere with conception.

Insemination is completed using a specially designed plastic insemination pipette. Naturally, all equipment used must be sterilized in advance of use. It is preferable to use disposable equipment to completely eliminate the possibility of contamination.

It’s especially important to be familiar with your mare’s estrus cycle and to know when the last forty-eight hours of the cycle will occur. Semen introduced by artificial it insemination should remain viable for a minimum of forty-eight hours. You’ll want to be sure to catch the ovulation window.

If you need to transport semen for artificial insemination, you can cool the semen (mixed with semen extender) to a temperature of 39.2°F and package it properly for transport. Be sure that it will be delivered as quickly as possible. Remember that the semen will not be viable after forty-eight hours have passed.

The positives to artificial insemination are clear. It is a cleaner, safer process all around. It is also very useful when the stallion and mare are in far flung locations. The downside is the need for technical expertise and the expense involved.

If you are interested, here is a bit more about horse reproductive cycle.


  1. Veterinary Guide to Horse Breeding
  2. Equine Reproductive Procedures
  3. Merck Veterinary Manual

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