In vitro fertilization has four basic steps:
Aspiration is the process where oocytes are harvested from the ovaries of a donor cow. The aspiration process entails using ultrasound for the technician to see the ovaries and a needle is used to extract oocytes from the ovaries. A donor cow must be 1.5 months after calving and can even be in the early stages of pregnancy (provided the ovaries can still be reached) for aspiration to take place. Aspiration can be repeated every 2 weeks and is usually done without hormone treatment(some cases may justify the need for small doses of hormones). Aspiration can be done either on farm or at our facilities in Brits, NW.
Oocytes are “matured” for a day in the laboratory before they are fertilized with the semen of the bull of your choice. Although all semen collected from bulls conform to certain standards for artificial insemination, results may vary for in vitro fertilization beteen bulls and for this reason semen from more than one bull can be used for fertilization in order to spread risk. One dose of semen can also be used to fertilize the oocytes of more than one cow.
The embryos are cultivated in an incubator for a further 7 days in the laboratory. After this cultivation the embryos can either be transferred to recipient animals or frozen. Generally IVF embryos do not freeze well and common practice is to transfer them to recipient animals as soon as the cultivation process is done.
The transfer of IVF embryos to recipient animals is done in the standard ET procedure. Transfers can either be done at our centre in Brits where recipient animals are sent to our facilities or on farm where the IVF embryos are transported in an incubator to your farm for transfer to recipient animals. In cases where there are more IVF embryos than recipient animals the rest will be frozen for transfer at a later stage.