Artificial insemination (A.I.) is the placement of semen into the uterus of a mare at the time of ovulation. It is performed by means of a catheter inserted through the mare's cervix by a veterinarian.

A.I. is used in horses for a number of reasons including the availability of the stallion, as an aid in managing mares with reproductive difficulties, to decrease the workload and increase the efficiency of the stallion, in the event of injury to the mare or stallion which may prevent normal service and in controlling venereal disease.

Successful A.I. involves regular ultrasound examination and monitoring of the mare's cycle and necessitates close communication between the mare owner, the veterinarian and the semen provider.

Three methods of A.I. are used in horses:

• Fresh semen is collected and used almost immediately on the farm at which it is collected, this method enables more efficient use of the stallion and may help pregnancy rates for stallions of marginal fertility.
• Chilled semen involves collection, dilution with extender, cooling and transport of semen to the mare for use within 36 hours. This method can be used from any fertile stallion from any location that can ensure reliable transportation of the semen to the mare.
• Frozen semen is collected and extended then frozen and stored in straws in liquid nitrogen. This technique allows access to semen from horses which are located overseas, currently competing, injured or even dead. Using frozen semen is convenient because the semen is available to be used when needed, but requires more intensive management of the mare as the technique demands timing of insemination close to ovulation of the mare's follicle.

Auckland Vet Centre has several experienced equine reproduction veterinarians able to advise and assist in managing mares for artificial insemination whether it is with fresh, chilled, or frozen semen.

Call us to discuss how these techniques can be used to assist you in breeding your mare.