Animal unit (AU)
A 1,000-pound beef cow is the standard measure of an animal unit. The dry matter forage requirement of one animal unit is 26 pounds per day. Animal unit equivalents (AUE) are calculated for various other animals. A 700-pound steer is 0.80 animal units. A 1,300 pound horse is 1.20 animal units. A 120-pound sheep is 0.20 animal units. Federal land management agencies, such as the Bureau of Land Management and the Forest Service, may use different standards for setting grazing fees. The Natural Resources Conservation Service uses animal units to estimate manure production and manure nutrient content when designing projects under the Environmental Quality Incentives Program (EQIP). EPA does not use the term animal units to define size classes for purposes of compliance with effluent limitations for Concentrated Animal Feeding Operations (CAFOs). Instead it sets thresholds by specifying the actual number of animals (40 CFR 122.23).