[Transplantation of embryos in sheep breeding]

Intra- and inter-breed transplantations were carried out with Bulgarian fresh embryos and with frozen embryos imported from Poland. A complex biotechnology was worked out, including methods of estrus synchronization, of inducing superovulation, and of producing, morphologic evaluation, storing, and transplantation of sheep embryos. Discussed are the possibilities of using embryo transplantation in sheep breeding for the fuller use of the reproductive potential of elite ewes as donors of embryos, for the introduction of new genotypes by means of importing frozen embryos as well as a modern model for fundamental investigations in the reproductive and cell biology.