The researchers from the Johns Hopkins University Bloomberg School of Public Health and Arizona State University looked for drug and other residue in the feather meal.
The findings were a surprise to scientists because fluoroquinolone use in U.S. poultry production was banned by the U.S. Food and Drug Administrationin 2005. The ban was put in place primarly because fluoroquinolone's resistance to the bacteria Campylobacter was increasing at a rapid clip.
The findings of the research were published March 21 in the publication Environmental Science & Technology.
The study marks the first time investigators have examined feather meal, a byproduct of poultry production made from poultry feathers, to determine what drugs poultry may have been given before being slaughtered and sold.
Poultry feathers are often turned into feather meal, which is then added as a supplement to poultry, pig and fish feeds or sold as organic fertilizer.
Antibiotics are introduced into the feed and water of poultry, primarily to make them grow faster. About 13.2 million kilograms of antibiotics were sold in 2009 to the U.S. poultry and livestock industries, which represented nearly 80 percent of all antibiotic sales for use in humans and animals in the country that year, according to the study.