It is the process of creating embryos from unfertilised egg cells called oocytes. The oocytes are gently sucked (aspirated) from the ovarian follicles by means of a fine needle, guided by an ultrasound scanner probe placed in the vagina. This is called Ovum Pickup (OPU) The recovered oocytes are then matured and fertilised in the laboratory. Further maturation and culture takes place in an incubator for approx. 7 days resulting in viable embryos which can be transferred into recipient cows or frozen and transferred at a later date.