Feathers are one obvious byproduct of chicken slaughtering, and waste not, want not, right? So feathers are processed into meal, which can then be used in a number of ways–among them fertilizer, and as an additive to feed for chickens, pigs, fish, and cattle.

 

We already knew that chickens receive antibiotics in their food and water supplies, just as other farm animals do. It was also known that some antibiotic residues persisted on chicken feathers–another potential driver of resistance in farm animals.

 

It turns out that many of these drugs accumulate in poultry feathers, so by testing feathers we have a non-invasive way of learning about what drugs are actually fed to poultry.

 

So what we’re seeing here are the presence of antibiotics and other drugs in feather meal, which is spread around as a fertilizer or fed to many species of domestic animals as an additive.

It’s difficult to keep up with these additional feed additives–in addition to feather meal, many animals could also receive distiller’s grains in their diet, ethanol by-products which are another potential source of antibiotic residues.

 

The paper notes that the Chinese samples are relevant as well–while most feather meal used here is domestically produced, we do import some, and about a quarter of what we import is from China, where antibiotics that are restricted or banned in the U.S. may still be in use.

Furthermore, farmers may not even know this is in the feed they’re using, as many mixes are proprietary. 

 

Source: http://scienceblogs.com