[Experiments with embryo transplantation in cattle in Bulgaria]

Summarized are the results of the first attempts to transplant embryos in cattle in this country over the 1979-1982 period. An average of 6.4 ovulations have been obtained by the induction of superovulation in 48 donor heifers with the use of gonadotropic preparations (Gestyl, Anteron, Folligon) in the middle of the luteal phase at dose of 2000-2500 IU as well as with prostaglandine preparations (Estrumate, Oestrophan) injected 48 hours later. Surgical and nonsurgical methods were employed to recover a total of 78 ova (25 per cent of those that ovulated). Sixty-one (78 per cent) of them were fertilized. Forty-seven (77 per cent) of these were classified as suitable for transplantation. The surgical transplantation of 46 embryos at the age of 7 days (either morula or blastocyst) in 30 synchronized recipient heifers resulted in 9 cases of pregnancy. Three calves were live born.