New research raises questions about whether poultry producers might still be using an antibiotic that was banned in 2005 after being linked to increasing antibiotic resistance.

Researchers at Johns Hopkins Center for a Livable Future (CLF) and Arizona State University tested feather meal -- a byproduct made of ground-up poultry feathers commonly added to chicken, swine, cattle and fish feed -- and found a surprising variety of drug residues, including fluoroquinolones, a class of antibiotics critical for fighting infections in humans.

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