It is now nearly fifty years since the first equine pregnancy from frozen semen was reported in Guelph in Canada. Until the last ten years however progress in Equine AI has been fairly slow and it is only since then that the technique has become popular. This increased popularity has coincided with an increase in the technical ability to freeze stallion semen well and the advent of real-time ultrasound scanning which has allowed the mares ovulation time to be pin-pointed.

There are a number of big advantages to be gained from using AI:

1. Ability to use superior stallions and those that are geographically impossible to use naturally.
2. Decreased risk of injury to mares and foals.
3. Virtually no risk of spreading disease.
4. Stallions can still be used after death
5. Stallions can continue to compete while producing foals

Conception rates are now very acceptable using frozen semen. This is the result of intensive management of the mare and manipulation of her oestrus cycle using reproductive drugs. Treatment of the mare after insemination has also changed in recent years and this has served to bring conception rates very close to that seen in natural service.