Purdue aims for bigger pigs

West Lafayette, Ind.-

Purdue University researchers are determined to better understand how ractopamine, a feed additive, speeds growth in hogs and makes them leaner.

Ractopamine hydrochloride, a popular supplement, reportedly begins to lose its effectiveness seven to 10 days after initial feeding.

Hogs can become desensitized to ractopamine when fed as a daily ration, resulting in fleeting growth benefits of the metabolism-modifying drug, according to Dr. Scott Mills, Purdue associate professor of animal science.

His paper was posted online in the Journal of Animal Science.

Mills and his research team are investigating molecular pathways involved when the supplement converts nutrients from fat to muscle tissue.

"We want to know what we can do to prolong the benefits of ractopamine and to circumvent desensitization," Mills says.

Ractopamine, sold by Eli Lilly and Co. as Paylean, is part of a group of compounds called beta-adrenergic agonists, which can be used to treat asthma and other human diseases. Ractopamine is the first of its class to be FDA-approved for swine growth.