Animal scientists in Brazil have found that a small dose of the feed additive ractopamine can boost pork production without changing how pork looks or tastes.

In the latest issue of the Journal of Animal Science, researchers said that a 5 mg/kg dose of ractopamine increased muscle mass and feed efficiency, and had no noticeable effect on pork marbling, fat content, toughness or color. The researchers came to this conclusion by testing pork from 340 pigs raised under commercial conditions. "We found that if [pork producers] use 5 mg/kg of ractopamine in the finishing diet of swine that should result in no detrimental effects on fresh pork quality and cooked pork palatability," said Natália Bortoleto Athayde, an animal scientist at Sao Paulo State University in Brazil.

However, some scientists have reported reduced pork quality with higher doses of ractopamine. The researchers found that pork from the 10 mg/kg pigs was lighter and less tender than pork from control group pigs. Athayde said this confirms previous studies showing that 5 mg/kg is an appropriate dose in Brazilian commercial pork production. "Pork is the most animal protein consumed in the world, and Brazil is currently the fourth-largest producer of this meat," said Athayde. "We export about 15 percent of pork we produce and we believe it is extremely important to know the quality of the meat that we offer to the world."

Athayde said she recommends further studies of how ractopamine affects animal behavior, consumer health and the environment.