Animal feeding operations (AFOs) are agricultural enterprises where animals are kept and raised in confined situations. AFOs congregate animals, feed, manure and urine, dead animals, and production operations on a small land area. Feed is brought to the animals rather than the animals grazing or otherwise seeking feed in pastures, fields, or on rangeland. There are approximately 450,000 AFOs in the United States. Concentrated animal feeding operations (CAFOs) are a relatively small number of AFOs that are regulated by the EPA.