Procedure

The embryo transfer begins with breeding the donor mare (the mare "donating" the embryo). 

Bred as usual, she is monitored with frequent ultrasounds to establish the exact ovulation time (when her egg is released).

At the same time, the recipient mares (the mares potentially "receiving" the embryo) are also monitored by ultrasound. We look for mares in the herd whose reproductive cycles match the donor mare.

7-8 days after the ovulation the donor mare's uterus is flushed. The fluid from her uterus is run though a special filter cup designed to isolate the embryo.

The flushed fluid is thoroughly searched for an embryo under a microscope. A 7-day embryo is approximately ¼ to ¾ millimetre in size. It is just visible to the naked eye.

As soon as the embryo is found it is graded, washed and transferred into a waiting recipient mare.

5 to 6 days later we know if the embryo transfer was successful.