Manipulation of fertility in domestic animals

For many years artificial insemination has been widely used for the manipulation of fertility in farm animals and more recently methods for the synchronization of oestrous cycles, superovulation and embryo transplantation have been increasingly applied. These techniques now provide new opportunities for the manipulation of gametes and embryos which might further enhance reproductive potential through the production of embryos in vitro, their preservation by deep freezing, cloning from embryonic cells or genetic manipulation to increase fecundity.