Bull semen is not created equal. But Peter Sutovsky has found a way to better the odds.
Sutovsky, an MU associate professor of reproductive physiology, has identified a way to remove a portion of faulty bull sperm from the artificial insemination of cattle.
While many farmers buy bulls and approach breeding the old-fashioned way, a host of factors can make bulls infertile at certain times. That’s why more farmers are turning to artificial insemination. Any advancement in reducing bad sperm in the artificial insemination process saves cattle ranchers time and money.
Sutovsky’s surprising method to better the odds of cattle insemination involves use of a magnet, metal particles and a sperm-filled test tube. The technique essentially separates the wheat from the chaff.
Researchers use “biomarkers” to identify sperm that will not bring about conception. One biomarker is ubiquitin, a protein found in most tissues that migrates to the surface of bad sperm.
Sutovsky coats small metal particles with an antibody that bind to ubiquitin on the defective sperm. He uses a magnet to literally pull those metal-sprinkled cells downward in the test tube. Next, he skims off the good sperm from the top.
“In the lab we use a very simple, regular magnet,” Sutovsky said. “It’s a little stick with three magnets on it. You put three test tubes on it and within a few minutes it pulls down all the metallic nanoparticles and the bad sperm with it.”
For the cattle industry, these advancements mean better fertility through artificial insemination. Costs are reduced because smaller semen doses are used to get equal or better pregnancy rates in a cowherd. The standard artificial insemination dose is about 20 million sperm; Sutovsky’s process makes pregnancy possible with 10 to 15 million sperm.
The process also works with other animals.