[Possibilities of ovum pickup in cattle].

Cattle breeding has a new reproduction technique in addition to artificial insemination and embryo transfer. It is the collection of ova from living animal by means of ultrasound guided follicle aspiration (ovum pick-up), followed by embryo-production in vitro. Follicles larger than 2 mm were punctured and the ova were collected twice weekly during 3 months. In total 1677 ova were collected from ten cows; 1342 (80%) were used for in vitro maturation, fertilization, and embryoculture. All ova were fertilized with semen from one bull, and 218 transferable embryos were produced. Calculated on a year basis, this would amount to 87 embryos per animal, with an intra-animal variation between 28 and 132. This new technique may replace MOET (Multiple Ovulation and Embryo Transfer; yearly average of 25 transferable embryos per animal), if the embryo-production via OPU can be performed with semen from any selected bull.