sealPurdue News

September 2000

Hog feed additive creates leaner pork

WEST LAFAYETTE, Ind. – At the state fairs this year, visitors were able to see hunkier hogs, thanks to a new pharmaceutical feed additive being fed to pigs.

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Paylean, a feed additive first sold to farmers this summer, can increase lean muscle gain in hogs by as much as 34 percent by reducing the amount of extra fat that surrounds the pork, says Brian Richert, assistant professor of animal science at Purdue University.

"There's night and day difference. It's Arnold Schwarzenegger's body versus mine," laughs Richert. "The pigs will look physically better when they are fed Paylean. They are much more heavily muscled."

Paylean went to market in the first week of July and many farmers are trying it. "They sold enough product in the first two weeks to feed a third of the pigs in the country," Richert says.

Paylean is the trade name for ractopamine hydrochloride, a pharmaceutical product that causes the hog's metabolism to shift nutrients from fat to muscle growth. It is a type of drug known as a beta-agonist; it is not a steroid, antibiotic, or biotechnology product. It is manufactured by Elanco, a division of Eli Lilly Co. of Indianapolis.

"Paylean is a highly water-soluble compound, so it leaves the animal very quickly," says Allan Schinckel, professor of animal science. "Other beta-agonists are not nearly as water soluble. That was part of the issue that prevented other compounds from being approved."

Because the compound leaves the hogs so quickly, Schinckel says there is no danger, or benefit, of people getting larger muscles by eating porkchops from pigs fed Paylean. "In research trials using rats, they found that a person would have to eat hundreds and hundreds of pounds of pork in a day before there would be a measurable change in their physiological metabolism," Schinckel says.

Consumers need not worry about the quality of their pork, either. According to Schinckel, Paylean has no effect on pork's nutritional quality, color, firmness or water retention (which helps determine how dry the meat is).

Even the marbling, which is the amount of fat in the meat and is important for the flavor, isn't changed with Paylean.

"There is really no change in intramuscular fat. Paylean reduces back fat and subcutaneous fat, which most people trim off," Schinckel says. "The only change is that there has been a slight increase in shear force, so the meat may be slightly less tender."

Leaner doesn't always mean better when it comes to meat, because fat helps to give meat flavor, texture and moisture. Making pork leaner than it already is could result in reduced consumer acceptance. However, the researchers point out that Paylean does not reduce the fat in the meat, just the fat surrounding the meat, which is generally trimmed off by consumers.

"The company's research studies have shown no change in pork quality, but that's not a given with today's pigs," Richert says. "Pork quality is already marginal with today's pigs because of the heavy emphasis on lean meat percentage, and we'll be watching the Paylean pork and asking, 'Does this product push us over the edge?'"

This summer, Richert and Schinckel conducted the first independent research trials that looked at how well Paylean works in leaner hog lines. Their previous research trial found that during the last 90 pounds of live weight gain before slaughter, Paylean increased fat-free lean growth. The average increase was 34 percent for hogs fed a dosage of 20 parts per million and 23 percent for hogs fed 10 parts per million. These increases in lean growth were consistent for hogs ranging from 220 pounds to 280 pounds.

The research also found that the percentage of lean growth was consistent among different types of hogs, even those bred to have reduced fat. "Paylean complements genetic lines with high lean-growth potentials by increasing their advantage over average genetic lines," Richert says.

The research was funded by Purdue and Pig Improvement Co. of Franklin, Ky.

Schinckel says it would take animal scientists 14 years to breed hogs as lean as those raised on Paylean. "A 240-pound pig on Paylean is going to have as much lean meat as a 260-pound hog raised without it," he says. "The benefit to the hog producer is that he won't have to feed the pig to the same weight to get the same amount of lean meat, and can save time and money."

Complete details of how hog farmers can best use Paylean can be found on the Purdue Pork Pages web site.

Sources: Brian Richert, (765) 494-4837;

Allan Schinckel, (765) 494-4836;

Writer: Steve Tally, (765) 494-9809;

Related Web sites:
National Hog Farmer magazine article on Paylean
Freedom of Information summary of FDA approval of Paylean



Brian Richert, assistant professor of animal science at Purdue University, uses an ultrasound device to measure the thickness of backfat on a pig that has been fed Paylean, a new feed additive. Richert and Allan Schinckel, professor of animal science, have conducted the nation's first independent nutrient trials on Paylean. (Purdue Agricultural Communication Service photo by Tom Campbell)

A publication-quality photograph is available at the News Service Web site and at the ftp site. Photo ID: Richert.paylean

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