In Vitro Fertilization (IVF), also called as “test tube baby” technology, means a process that an unfertilized egg (oocyte) is fertilized by a sperm in the dish to generate an embryo. In cattle, cumulus oocyte complexes (COCs) are extracted from the follicles of ovaries either from slaughterhouse or from the ovaries of genetic elite donors by Ovum Pickup (OPU), or ultrasound-guided trans-vaginal oocyte recovery. The COCs are usually matured in vitro (IVM) for 20-24 h before being fertilized later in the laboratory. Fertilized eggs are subsequently cultured in vitro (IVC) for 7 days until they develop into blastocysts. The developed blastocyst is implanted into the uterus of a recipient by embryo transfer (ET) technique. Those embryos can also be frozen by either traditional slow freezing procedure or vitrification method. Conventional semen (50X: 50Y), sex sorted frozen semen, or frozen semen with reverse sorting technology can be used for IVF.
During IVF process, sperm capacitation is a critical process for the success of fertilization. This can occur in vitro in the absence of reproductive tract fluids with the use of compounds such as calcium ionophore or progesterone, and glycosaminoglycan (GAGs), such as heparin.
IVF is a feasible and potentially efficient approach to increase the fertilization efficiency of sex-sorted sperm, especially for the ovum pickup (OPU)-IVF, which has been widely used to produce genetically valuable offspring from elite female donors.