The donor mare must be synchronised with a suitable recipient mare. The recipient should be a maiden or a highly fertile proven foal producer of less than ten (10) years of age. The recipient must be synchronised to ovulate at a certain time after the donor. This requires synchronisation of several recipients to ensure that at least one will be suitable. The Equine Breeding Centre keeps a herd of recipient mares for this purpose.
The donor mare should be scanned to determine the optimum time of service and can then be served naturally or inseminated with fresh, chilled or frozen semen. Fertilisation should occur and the fertilised egg will remain in the oviduct for six (6) days before descending into the uterus. It can then be flushed from the uterus (usually between 6 ½ & 7½ days depending on mare & semen factors) and transferred immediately into the recipient, non-surgically (similar to AI).
The recipient mare can be examined by ultrasound for pregnancy on day 14 (seven days after transfer). Some pregnant recipients may be maintained on a hormone (RegumateP) for up to 60 days after transfer, however in most cases the RegumateP may be stopped at 22 days of embryo age.