Sexing Semen

By: Delaney Booth & Jordan Bride

Why is it Important?

Sexed semen can help dairy farmers make sure more female calves are born. However, the conception rate is slightly lower with sexed semen, particularly for cows already being milked, so that it is mainly recommended for heifers who will be having their first calf.

The History of it

After a very long history of unsuccessful attempts to differentiate between mammalian sperm that produce males from those that produce females, a breakthrough came in 1981 when it was demonstrated that precise DNA content could be measured. Although these initial measurements of DNA content killed the sperm in the process, they led to the ultimate development of a sperm sorting system that was capable, not only of differentiating between live X- and Y-sperm, but of sorting them into relatively pure X- and Y-sperm populations without obvious cellular damage.

How it's Done

1.A piezo electric crystal is undulated approximately 90,000 times a second, which breaks the stream into droplets at a particular point in time. The location of the last-attatched droplet in the stream is highly controllable.

2. An X- or Y- bering sperm is compared to a preset criteria.

3. After a time delay, the insertion rod is charged.

4. A charge is applied at the time the cell reaches the last attached drop.

5. The charged droplets are deflected as they pass between continuously charged plates.

6. Particles not reaching the criteria drop straight down to waste.

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