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Adding Antibiotics to Chicken Feed Not Cost-Effective


The widespread practice of adding antibiotics to chicken feed for growth promotion is not cost-effective, according to a study by Johns Hopkins Bloomberg School of Public Health researchers. They found that increases in the size of antibiotic-fed chickens did not offset the added cost of the antibiotic feed. Overall, farmers lost about one penny per antibiotic-fed chicken. The study, published in the January-February 2007 issue of Public Health Reports, is the first economic analysis of the use of antibiotics in poultry.

For the study, Jay Graham MBA, MPH, and Ellen Silbergeld, PhD, of the Bloomberg School’s Center for a Livable Future, and John Boland, PhD, an emeritus professor in the Department of Geography and Environmental Engineering in the Johns Hopkins University Whiting School of Engineering, analyzed the marginal profits associated with drug additives in comparison to the costs of utilizing these drugs. The data used in the analysis were compiled by the Perdue Corporation, a leading broiler poultry producer. In 2002, Perdue discontinued use of antibiotics in its poultry.

The results of the economic analysis indicated that the net effect of using growth-promoting antibiotics in feed was a loss of $0.0093 per chicken, or about 0.45 percent of the total cost per chicken. The results do not include potential changes in veterinary costs from switching to antibiotic-free feed or medical and public health costs incurred from treating antibiotic-resistant illnesses.

“Although Perdue has discontinued the use of growth-promoting antibiotics, our study remains relevant both in the United States and internationally. Roughly two-thirds of the 8.7 billion broiler chickens raised in this country are fed antibiotics throughout their life. Internationally, poultry production is growing rapidly, mostly in developing countries where there are limited controls on antibiotic use for animals. Further, the results of our study help dispel the myth that growth-promoting antibiotics are vital to raising poultry,” said Graham, lead author of the study and a pre-doctoral fellow with the Center for a Livable Future.

“The public health community has long had concerns about the potential misuse of antibiotics in food animal production. This practice has been associated with the dangerous increases in the number of antibiotic-resistant infections in people worldwide,” said Silbergeld, co-author of the study and professor in the Department of Environmental Health Sciences at the Bloomberg School of Public Health. “Our study considered the economic costs and benefits of antibiotic feed additives, and the results suggest that the industry should rethink its practices from a business perspective.”

Growth Promoting Antibiotics in Food Animal Production: An Economic Analysis” was written by Jay P. Graham, MBA, MPH, John J. Boland, PhD, and Ellen Silbergeld, PhD.

Funding for the research was provided by the Johns Hopkins Center for a Livable Future.

Public Affairs media contacts for the Johns Hopkins Bloomberg School of Public Health: Tim Parsons or Kenna Lowe or at 410-955-6878 or