In Vitro Fertilization
IVF is a technique in which the oocytes are extracted from the donor cow by a method of aspiration from the reproductive tract. This ooytes are then selected 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 had been made. The embryos stay in the medium until the 7th day when they are ready to be transfer.
This technique has three main advantages over the conventional In Vivo embryo collection. With IVF it is not necessary to super ovulate the cows and it is not necessary to synchronize them either. This is a major break through since the donor cows are not exposed to hormones that might compromise the reproductive soundness of the animals and they can be worked without a previous preparation time for the procedure. The average of embryos produced is running at about 30% of the oocytes harvested, 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 reduced the generation interval for the animals with a specific desirable trait.
