Mares can be mated or “covered” in one of two ways. The first and most obvious is when they are naturally mated. The second is where semen is collected from a stallion, which maybe on a different continent, stored, and at a later date, placed into the uterus of the mare. This process is known as artificial insemination (AI).

Natural Mating

Mares are often covered naturally, especially in the thoroughbred industry. In some instances the stallion will be free to run with the mare whilst at other times the stallion covers the mare every other day whilst the mare is in season. In the thoroughbred industry, this technique has been developed further: the mare is examined by a veterinary surgeon and then if deemed to be in season the stallion will be allowed to mate with her. The mare is then regularly rechecked for signs of ovulation and ultimately pregnancy.

Artificial Insemination (AI)

Within the non-thoroughbred industry, the use of AI is becoming more and more popular. Fresh, chilled or frozen semen can be used.

The advantages of AI include:

• Reduced risk of spreading venereal diseases as there is no direct stallion-mare contact
• Reduced risk of injury to the horses
• Achieves matings whilst the sire and dam are on different stud farms, or even in different countries.

Artificial insemination involves collecting semen from the stallion and then implanting it into the mare. The semen is collected by having the stallion mount a teaser animal or dummy. Once mounted, his penis is positioned into an artificial vagina (AV) and the semen collected. The semen is then either used immediately or is frozen, stored and then transported to the stud farm where the mare is stabled. The mare is then inseminated once she is in season. The semen is thawed (if frozen) and inserted into the mares vagina via a pipette.

If you are considering breeding from either a mare or stallion your veterinary surgeon will be able to provide you with further advice as to which method is appropriate for you.