Artificial insemination is not a new way of breeding mares; it has been used for centuries in many different countries although the modern and highly clinical type of artificial insemination (AI) now practiced has a much more recent history. In the United Kingdom and Europe AI has been used since 1890, but has recently become much more popular in the development of the warm blood and sport horse breeds. The countries considered to be on the cutting edge of AI technology development in horses include France, Germany, Denmark and Holland. AI allows the breeder to import semen from any stud standing for AI collection in the world without having to either ship the mares to the stallion or the stallion to the mares. Not only does this cut down on the cost of this highly selective type of breeding program but it also provides more safety for the mares and the stallions as there is less transportation and stress on the horses.
In addition to just preventing possible injuries in transportation, AI also prevents possible injury during the natural breeding process. It is not uncommon for mares and stallions to be kicked or become very aggressive towards each other during mating, so AI can allow mares to become impregnated without exposing either the mare or the stallion to each other. Diseases such as equine herpes virus, equine metritis, and other contact type of bacterial and viral infections that can be passed from the mare to the stallion or vice versa during natural mating are completely eliminated using the artificial insemination process.
Artificial insemination may actually benefit the viability and quality of the semen as well. In AI programs the semen is only collected every other day rather than having the stallion attempt to breed multiple mares all within their fertility timeframe. The process allows the semen to be immediately frozen, preserving the semen for use when the time is right. The frozen semen can be kept indefinitely providing the refrigeration units and environment is properly maintained.
The AI system of semen collection also allows for each individual collection to be tested for quality and viability of sperm. In a typical natural type of breeding, known as service, the stallion's sperm is not evaluated, which means that the breeder must wait until the mare can be tested for confirmation before he or she knows if the semen was viable. In AI the semen is tested before it is used in breeding the mare. This helps breeders understand if it is a reproductive failure on the part of the mare or the stallion if she does not test as pregnant.
Since older stallions have a lower sperm count than younger stallions, AI allows technicians to formulate the sperm that is to be deposited in the mare and ensure that the correct number of viable sperm are available to fertilize the egg. This means that stallions even at the age of 20 or more years of age can still be used in AI programs, even though they would not typically be able to service a mare if used in natural breeding programs. Finally, the process also helps mares that may have a physical reason that they cannot be naturally bred. AI provides an alternative to natural impregnation that can make these mares possible as broodmares.