ABSTRACT
Introduction Several advanced assisted reproduction procedures require transfer of embryos into recipient mares. In some instances the original embryo may be produced in vivo and in other cases the embryo may be produced in vitro by intra-cytoplasmic sperm injection (ICSI) or somatic cell nuclear transfer (NT). Conventional in vitro fertilization (IVF) is still problematic in the horse, with only 2 live foals born in France reported in 1991. The IVF foals were produced from in vivo matured oocytes collected from gonadotropin-stimulated donor mares. There are currently no reports of live foals produced from in vitro matured oocytes and conventional IVF.
