Poultry feathers bioaccumulate antimicrobials, feather meal a risk
Feathers can be seen as the tissue on par with faeces, hair or fur: the organism pushes out unwanted substances through them, and hence are a form of excreta: a way for a body to eliminate harmful products. Since the feathers in some cases are re-used as a feed supplement, poultry feathers may be introducing pharmaceuticals into the human feed supply.
Much in the same way that researchers once sampled Napoleon Bonaparte’s hair to test for arsenic poisoning, poultry feathers accumulate the antimicrobials administered to poultry, new research undertaken John Hopkins University and Arizon State University has shown.
Antimicrobials used in poultry production have the potential to bioaccumulate in poultry feathers but available data are scarce. Following poultry slaughter, feathers are converted by rendering into feather meal and sold as fertilizer and animal feed, thereby providing a potential pathway for reentry of drugs into the human food supply.
Feather meal (n = 12 samples) was analysed for 59 pharmaceuticals and personal care products (PPCPs) using EPA method 1694 employing liquid chromatography tandem mass spectrometry (LC/MS/MS).
All samples tested positive and six classes of antimicrobials were detected, with a range of two to ten antimicrobials per sample. Caffeine and acetaminophen were detected in 10 of 12 samples. A number of PPCPs were determined to be heat labile during laboratory simulation of the rendering process. Growth of wild-type E. coli in MacConkey agar was inhibited by sterilized feather meal (p = 0.01) and by the antimicrobial enrofloxacin (p < 0.0001) at levels found in feather meal. Growth of a drug-resistant E. coli strain was not inhibited by sterilized feather meal or enrofloxacin.
This is the first study to detect antimicrobial residues in feather meal. Initial results suggest that more studies are needed to better understand potential risks posed to consumers by drug residues in feather meal.