Animal feeding operation
The United States Environmental Protection Agency (EPA) defines an animal feeding operation (AFO) in the Code of Federal Regulations (CFR, Federal Register, V. 68 No. 1, page 7265) as a lot or facility (other than an aquatic animal production facility) where the following conditions are met: Animals (other than aquatic 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, and Crops, vegetation, forage growth, or post-harvest residues are not sustained in the normal growing season over any portion of the facility.