Selection of embryo recipients, a real challenge in cows embryo transfer programs

Abstract

This article comes as a response to a clinical situation that the members of our team found at an embryo transfer program. At the moment of insemination, day 7 after estrus period, a high number of untransferable recipients was found after ovaries ultrasonography. From 54 animals synchronized, just in 5 (9.25 %) cases was performed the embryo insemination. The embryo transfer was performed in cases where a corpus luteum (CL group) higher than 17 mm was found on the ovary, corpus luteum with a cavity of a maximum 10 mm and without a follicle higher than 10 mm on the ovary with the corpus luteum or on the other ovary. The rest of heifers were classified into the next groups: Hollow corpus luteum (HCL Group), 11 cases (20.37%), Lutheal cyst (LC Group), 5 cases (9.25%), No corpus luteum (NCL Group), 4 cases (7.40%), Corpus luteum and follicle (CLF Group), Small corpus luteum (SCL Group). Cystic corpus luteum seems to be a good variant for performing the Embryo Transfer. Even if the level of P4 concentrations in the case of a luteal cyst is highest, the embryo transfer in these cases is with a high level of risk and should be avoided.