A feedlot is an open space where animals are fattened before slaughter. Beef cattle usually arrive at the feedlot directly from the ranch or farm where they were raised, while poultry and pigs often remain in an automated feedlot from birth until death. Feed (often grains, alfalfa, and molasses) is provided to the animals so they do not have to forage for their food. This feeding regimen promotes the production of higher quality meat more rapidly. There are no standard parameters for the number of animals per acre in a feedlot, but the density of animals is usually very high. Some feedlots can contain 100,000 cows and steers. Animal rights groups actively campaign against confining animals in feedlots, a practice they consider inhumane, wasteful, and highly polluting.
Feedlots were first introduced in California in the 1940s, but many are now found in the Midwest, closer to grain supplies. Feedlot operations are highly mechanized and large numbers of animals can be handled with relatively low labor input. About half of the beef produced in the United States is feedlot-raised.
Feedlots are a significant nonpoint source of the pollution flowing into surface waters and groundwater in the United States. At least half a billion tons of animal waste are produced in feedlots each year. Since this waste is concentrated in the feedlot rather than scattered over grazing lands, it overwhelms the soil's ability to absorb and buffer it and creates nitrate-rich, bacteria-laden runoff to pollute streams, rivers, and lakes. Dissolved pollutants can also migrate down through the soil into aquifers, leading to groundwater pollution over wide areas. To protect surface waters, most states require that feedlot runoff be collected. However, protection of groundwater has proved to be a more difficult problem, and successful regulatory and technological controls have not yet been developed.
[Christine B. Jeryan ]
Kerr, R. S. Livestock Feedlot Runoff Control By Vegetative Filters. Ada, OK: U.S. Environmental Protection Agency, 1979.
Larson, R. E. Feedlot and Ranch Equipment for Beef Cattle. Washington, DC: U.S. Government Printing Office, 1976.
Peters, J. A. Source Assessment: Beef Cattle Feedlots. Research Triangle Park, NC: U.S. Environmental Protection Agency, 1977.