In a peer-reviewed article published today (Mar. 12) in "PLOS ONE," Guy Loneragan, a professor of food safety and public health in Texas Tech's College of Agricultural Sciences and Natural Resources, adds to this ongoing national dialogue. "Beta agonists improve the efficiency of beef production and this improvement provides important societal benefits," Loneragan said.

The beta agonists approved by the U.S. Food and Drug Administration for use in cattle increase muscle growth and may reduce the amount of fat the cattle accumulates, he said. This means the cattle converts more of the feed it eats into beef, and it does this more efficiently.

The article, co-authored by Daniel Thomson and Morgan Scott of Kansas State University, is titled "Increased mortality in groups of cattle administered the β-adrenergic agonists ractopamine hydrochloride and zilpaterol hydrochloride."

With the use of beta agonists, cattle require less feed and less water to produce the same amount of beef than if no beta agonists were used. Less land would be used to grow the crops used to feed the animals and, therefore, less fuel to produce the same amount of beef. The improvement in the efficiency of production has meaningful societal benefits.

"However, through our extensive analysis, we found that the incidence of death among cattle administered beta agonists was 75 to 90 percent greater than cattle not administered the beta agonists," Loneragan said. "This increase in death loss raises critical animal-welfare questions. We believe an inclusive dialogue is needed to explore the use of animal drugs solely to improve performance, yet have no offsetting health benefits for the animals to which they are administered. This is particularly needed for those drugs that appear to adversely impact animal welfare, such as beta agonists."

CONTACT: Guy Loneragan, professor, Department of Animal and Food Sciences, Texas Tech University at (806) 834-1291 or guy.loneragan@ttu.edu

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