The per capita consumption of poultry meat is greater than that of any other animal- or vegetable-derived protein source in the U.S. For every 3-kg (6.6 lb) chicken produced, over 1 kg or 33 % of the total mass is inedible and has no human food market. The byproduct from poultry slaughtering − heads, bones, viscera, and feathers − amount to billions of kilograms of inedible chicken parts and 2 billion kg of feathers.
The rendering industry processes poultry feathers into feather meal. It is sold as a fertilizer, a raw material in biodiesel, an ingredient in bioplastics and an animal feed ingredient. As a feed ingredient, feather meal can be added to poultry, pig, ruminant, and fish feeds. Feather meal is assessed for palatability, nutrient content, and animal weight gain. Contaminants such as antimicrobials have only recently been shown to accumulate in raw poultry feathers, and tests of antimicrobials in feather meal products have not been described in the literature.
D. C. Love, John Hopkins University, Baltimore, Maryland, USA, and colleagues analyzed feather meal (n = 12 samples) for 59 pharmaceuticals and personal care products (PPCPs) using EPA method 1694 employing liquid chromatography tandem mass spectrometry (LC/MS/MS).
All samples were tested positive. 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 Escherichia 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. More studies are needed to better understand potential risks posed to consumers by drug residues in feather meal.
- Feather Meal: A Previously Unrecognized Route for Reentry into the Food Supply of Multiple Pharmaceuticals and Personal Care Products (PPCPs),
D. C. Love, R. U. Halden, M. F. Davis, K. E. Nachman,
Environ. Sci. Technol. 2012, 46, 3795–3802.