In Vitro Fertilization
IVF is a technique in which the oocytes are extracted from a donor cow by a method of aspiration from the reproductive tract. Selected ooytes are then incubated for a period of 24 hours; this is call the maturation period. After maturation, the eggs are fertilized 18 to 22 hours after the co-culture has been made. The embryos stay in the medium until the 7th day, when they are ready to be transferred.
This technique has three main advantages over conventional In Vivo embryo collection. With IVF, it is not necessary to superovulate the cows, nor is it necessary to synchronize them. This is a major breakthrough since the donor cows are not exposed to hormones that might compromise the reproductive soundness of the animals, and they can be worked without prior preparation time for the procedure. Embryo production averages about 30% of the oocytes harvested, although this quantity varies depending on the breed, the donor cow, and also the mating. Another advantage with the IVF is that the animals can be aspirated every 20 days instead of every 60 as in In Vivo embryo collection. The other advantage of IVF is that the animals can be harvested at a very young age; this will create a major impact on breeding selection since it reduces the generation interval for the animals with a specific desirable trait.