Animal feeding operations (AFOs) are agricultural enterprises where animals are kept and raised in confined situations. As defined by the Environmental Protection Agency (EPA), and your state regulatory agency, an AFO is a lot or facility where animals have been, are, or will be stabled or confined and fed, or maintained for a total of 45 days or more in any 12-month period. Feed is brought to the animals rather than the animals grazing or otherwise seeking feed in pastures or fields or on rangeland. Animals are not considered to be stabled or confined when they are in areas such as pastures or rangeland that sustain crops or forage growth during the entire time that animals are present.
According to the EPA, there are approximately 450,000 AFOs in the United States.
Author: Chris Henry, Biological Systems Engineering, University of Nebraska