THE FIRST SUCCESSFUL EMBRYO-TRANSFER IN H ORSES IN HUNGARY .2.

This is the first report of sucessful embryo transfer in horses in Hun gary. The work has been carried out at the Experimental Institute of t he University of Veterinary Science in the autumn of 1994 and in the s ummer of 1995. Ovarian activity was followed by daily rectal examinati on and ultrasonography (ALOKA SSD-210 DX II, 5 MHz transducer, ALOKA C o., Japan) during the examination period. For the synchronisation of t he donors and recipients PGF(2 alpha) (Enzaprost 25 inj. A. U. V., San ofi, France) was used at 10 mg dose rate. In the first part of the stu dy (1994) 10 recoveries were performed on 8 mares on day 7 (day 0 = da y of ovulation) of the cycle. Out of the 10 attempts 8 was evaluated. In one case systemic disease was present and in the other case the beh aviour of the mare prevented the flushing. The 8 recoveries resulted i n 6 embryos (6/8 = 75%) (4 early and 2 expanded blastocyst) and 5 was considered to be of transferable quality (5/8 = 62,5%) (Figure 1). In the second part of the study (1995) 2 mares were used as donor and 3 a s recipient, respectively. 5 recoveries were performed and 2 embryos ( early blastocyst of excellent to good quality) and 1 oocyte were colle cted. The two embryos were transferred to recipients ovulating 1 or 2 days after the donors with non surgical, transcervical technique. 7 da ys after the transfer an embryonic vesicle was found in both recipient s but one of them underwent early embryonic death 2 days later. The ot her continued in normal pregnancy (Figure 2) and a living foal was bor n in the summer of 1996 (Figure 3).