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Sexed Semen

Advanced Use of Technologies

Trans Ova Genetics is able to gender select or sex/sort fresh or frozen semen for use in on-site in vitro fertilization (IVF). The application of this technology can increase the odds of creating embryos – and subsequently, offspring – of the desired gender. The sorting of previously frozen semen is called a “reverse sort”.

Breeders can choose the sire they wish to use on the aspirated oocytes or eggs from their elite donor females. This includes traditional non-sorted frozen semen, sorted frozen semen, or non-sorted frozen semen that will be thawed and reverse sorted. If the semen is delivered to the Trans Ova Genetics laboratory, it can be thawed and used in the fertilization process.

In the fertilization process, it is the bull’s sperm cell that determines the gender of the resulting offspring. The process of gender-sorting semen involves a flow-cytometer, which uses a series of dyes and light rays to detect a visible difference in DNA content between sperm cells carrying the X chromosome and cells carrying the Y chromosome. The X (female) bearing sperm contains 4% more DNA than the Y (male) bearing sperm which allows the sorting process to be facilitated.

The reverse sorting process can provide samples for fertilization with approximately 87-90% accuracy of the desired sperm cells. Embryos created with reverse sorted semen have been reported on average to be up to 90% accurate on the desired gender. Although most sires will sort accurately, the process can be affected by semen quality and concentration thus resulting in variation in embryo/live calf sex ratio. There is often significant variation among sires in fertility and embryo development rates.

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Frequently Asked Questions


Trans Ova Genetics does not provide insurance on domestic or International shipments. Ask us about what options are available.

No, Trans Ova does not collect bulls. However, fresh bull ejaculate can be delivered to a Trans Ova facility for IVF use and to be sorted. Contact your Client Service Representative for more information.

Locations Closer to Home!

Trans Ova Genetics is focused on developing IVF satellite locations where donors can be collected closer to their home.