Assisted Reproductive Technology
There are three distinct generations of assisted reproductive technologies (ART). Artificial insemination with fresh or frozen semen was initially described about six decades ago and has become a common horse management technique.
The second generation, ultrasonography and embryo transfer (ET), are about four decades old. Ultrasonography has become a widely used reproductive management technique in the horse in the past 20 years and allows for imaging of reproductive structures and sexing of fetuses. Embryo transfer is less comonly used in horses because of the inability to collect more than one embryo/cycle/mare and the cost.
The third generation of technologies includes embryo sexing, oocyte recovery and in vitro fertilization (IVF); gamete intrafallopian transfer (GIFT); zygote intrafallopian transfer (ZIFT); and intracytoplasmic sperm injection (ICSI), are less than 20 years old.These technologies are not commonly used in horses because of the inefficiencies, cost and lack of breed registry recognition.
