Artificial Insemination Process


The artificial insemination process in horse reproduction involves close management of both the stallion and the mare’s reproductive cycle.


The artificial insemination process begins with daily ultrasounds of the mare’s reproductive tract to follow the size of her follicles (the fluid filled structures on her ovary that contain the egg or oocyte) as well as the tone and condition of her uterus. The palpating veterinarian will look for the follicle(s) to reach a mature size (approximately 30-45mm in diameter) and for her uterus to form adequate endometrial edema. These two factors indicate that she is in a proper heat and ready to breed.


When the veterinarian has determined that the mare is ready for artificial insemination they will induce ovulation by giving a hormone to cause the mare to release her egg within the next 36-48 hours and arrange for collection of the stallion. Timing is critical as there is a small timeframe when the mare should be inseminated. Inseminating too far before or after ovulation and the chance of pregnancy greatly reduces and will increase the cost for the client from repeated shipments and cycle management fees. Because our priority is reproductive success without excessive cost, the veterinarians at Vista Equine monitor mares on a daily basis to try and pinpoint the optimal time for artificial insemination.


The second phase of artificial insemination is the management and collection of the stallion. Whether the stallion is standing at the farm where the mare is being bred or standing at a facility across the country, he is likely on a strict collection schedule. Most stallions are collected every other day from February through July. This strict collection schedule helps optimize his sperm cell production thus increasing the number of mares he can breed in a single season and potentially increase the number of pregnancies achieved.


The stallion will be collected using an artificial vagina while mounting a breeding phantom. Once he has been collected the semen sample will be evaluated for volume, progressive motility of the sperm cells, and concentration of the sperm cells. The sample will then be extended to increase the lifespan of the sperm cells and be divided into breeding doses.


Mares ready for artificial insemination at the same farm can be inseminated immediately following extending of the semen. Doses being shipped to another facility will be loaded into an Equitainer, a temperature controlled box or plastic shipping container, with coolant cans and will be shipped overnight for delivery at the other facility the following morning.


The key to a successful artificial insemination procedure is to have highly trained veterinarians managing your mare at all stages of her reproductive cycle. At Vista Equine, we take every precaution and implement quality standardized procedures to ensure the artificial insemination process goes as smoothly as possible which gives us the highest chance of pregnancy.