Practical aspects of equine embryo transfer

Abstract

This article focuses on practical aspects and most specific points of equine embryo transfer (EET). Induction of polyovulations in donor mares is not possible. Only the repetition of embryo collections can increase the number of foals from the same mares. At each oestrus, follicular growth and artificial inseminations are conducted in the same way as for any brood mare. It is essential to know the number and timing of ovulations at least a 12-hours accuracy. Induction of ovulation is frequently required, GnRH agonists are used to do that. Embryos are flushed from the donor mare’s uterus, typically on day 7 or 8 after ovulation using a long (~1.5 m) and large (diameter 8 mm) Foley-type balloontipped catheter introduced by vaginal route just in front of the cervix. Some practical details are important to EET practitioners, firstly, the embryos are easily located under stereo-microscope after filtration of flushing medium, and secondly most equine embryos