ABSTRACT
Among the small laboratory animals the most commonly used species for studies on egg transfer have been the mouse, rat, and rabbit. Other small animals in which egg transfer has been performed, though only to a limited extent, include four carnivores — the cat, the dog, the ferret, and the mink — and two rodents — the golden hamster and the Mongolian gerbil. The chapter describes that observations on these six species include transfer between species and to ectopic sites. In three extensive series of transfers involving cow, sheep, and pig eggs, it was established that fertilized eggs of each of these species could develop to the early blastocyst stage in the ligated rabbit oviduct; as a rule the younger the egg at transfer the longer the period of survival. Subsequently, follicular phase rabbits were used, thereby avoiding the need for synchronization.
