Ranchers who raise cattle for beef are running short of cows—and they're hoping to use technology to boost their odds of breeding more.
The method involves adding an extra step to artificial insemination. Instead of just impregnating cows with bull semen and hoping for the best, scientists can separate and collect the sperm with female characteristics.
The idea of "sexed semen" was first developed by the U.S. Department of Agriculture in the 1980s. The method relies on a simple idea: Cattle sperm with male characteristics tend to be a bit heavier than those with female traits, so they can be sorted at a microscopic level.
Dairy farmers have been using sexed semen for years, since they rely on a constant supply of milk-producing females. But most beef-cattle ranchers never had an urgent enough need to justify the steep expense.
Until now. Over the past two years, bone-dry conditions have decimated the beef-cattle herd. The price of meat has set records, and farmers are stuck with a slim supply of young females, known as heifers, to breed the next generation of livestock.
"We are facing historic shortages of cows," says Jeff Jorgensen, director of operations at King Ranch Inc. in Kingsville, Texas, one of the biggest calf producers in the country.
The best heifers could double in price over the next year, leaving most ranchers with little choice but to grow their own. And since it takes so long to produce new animals—females give birth to only a single calf a year—farmers need to choose the sex of the offspring.
So, many breeders say they've been inquiring about sexed semen and plan to pursue the idea.
"If you know you're going to get all heifers, that's pretty cool," says Daniel Mushrush, part-owner of Mushrush Ranches in Strong City, Kan., which has used sexed semen. He says ranchers will likely use more of it as pasture conditions improve and allow more of them to rebuild herds.
"There very definitely will be people who will use this to repopulate" breeding herds, says Aaron Arnett, vice president of beef genetics at Select Sires, a bovine-genetics company in Plane City, Ohio, that provides sexed semen, among other things.
Mr. Eckblad is a former reporter for Dow Jones Newswires. He can be reached at firstname.lastname@example.org.