Embryo flushing is the process where an embryo is flushed from a donor cow and transferred into a recipient (surrogate) where the embryo will develop.

Through embryo flushing a genetically advanced cow can produce more calves yearly than possible with natural mating. This improves the cow’s genetic ability over her lifespan.

In Vitro Fertilization (IVF) and In Vivo Embryo Flushing is considered to be the fastest and most cost-effective way to expand and preserve cow genetics worldwide. The same goes for semen collection under the bull genetics. Many breeders make use of this technique to increase the top genetics in their herds.

In Vivo embryo production is the process where a donor cow is injected with hormones (FSH) to ovulate multiple oocytes, which can then be fertilized with a selected bull (Artificial Insemination (AI) or Natural Mating). After insemination the gametes develop into embryos, which are then flushed from the donor cow 6 to 7 days after insemination.

With In Vitro Fertilization (IVF) the donors receive no hormonal treatment. Oocytes (egg cells) are aspirated directly from the ovaries via Ovum Pick-Up (OPU). The oocytes (female gametes) and matured in an incubator for 24 hours before fertilization, where semen (male gametes) is introduced. The gametes rest in the incubator for another 24 hours and then develop in a growth media until day 6 or 7.

Recipients, with lower genetic potential, are maintained at optimal condition and synchronized to receive one embryo from a donor cow, either In Vivo or In Vitro produced. After transfer the embryo or foetus develops in the surrogate until calving, where after she will raise the calf as her own.

The embryo’s survival rate from implantation to calving in the surrogate varies normally between 40% to 60%. Embryo quality plays a major role in the success of the transfer, as well as the rate at which the embryo develops, herd management, environmental factors, climate variations, the recipient breed and temperament.

In vivo embryo flushing can be repeated every 4-6 weeks, while IVF can be repeated every 7-14 days. It is a good idea to combine these two processes for example two cycles IVF and then one In Vivo Flush.

What is the difference between In Vivo and In Vitro Embryo Production?
IN VIVO: Embryo FlushingIN VIRTO: Ovum Pick-Up & In Virto Production
1. Early embryo development takes place in the donor cow1. Early embryo development takes place in an incubator with artificial media
2.Fertilization is done on donor using AI2.  Fertilization is done in the laboratory
3.Three to six semen straws are used to inseminate one donor3. One semen straw can be used to fertilize oocytes of up to 8 donors
4. The embryos exposure to external factors are lower, thus less risk4. Greater risk due to more handling of embryo and exposure to external factors.
5. Embryos are flushed from the donor cow5. Oocytes are aspirated from the donor
6. The donor is stimulated with

hormones for increased ovulations

6. No hormones are required

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