OVUM PICK-UP (OPU) IN THE COW

Intensive research during the last years has considerably improved the results of In Vitro Fertilisation (IVF). Within the framework of IVF it is very important to develop a technique which permits the prelevat ion of oocytes from previously selected animals. In 1988 the transvagi nal follicular aspiration under echogenic control, as conducted in hum an medicin, was modified for the cow. This was the start of several re search programmes concerning the factors influencing the egg recovery rate: superovulation, the frequency of puncturing the ovaries and its effect on the cows cyclicity. More recently, additional modifications on the OPU equipment made the technique economically more interesting. OPU has now proved to be a technique with a high repeatability and in combination with IVF it can become an alternative for the classical e mbryo transplantation programs. It may also be the ultimate solution f or some infertility patients. This review article considers briefly th e history of OPU and describes the OPU technique. It deals also with t he factors influencing the success of transvaginal follicular aspirati on.