Does size matter? Animal units and animal unit months

The concepts of animal units, animal unit months, and animal unit equivalents have long been used as standards for range management planning, estimating stocking rates, reporting actual use, assessing grazing fees, ranch appraisal, and other purposes. Increasing size of cattle on rangelands has led some to suggest that the definition of animal units and animal unit months requires revision. Range managers need to understand these concepts and arbitrarily changing them would lead to confusion. The Rangeland Assessment and Monitoring Committee reviewed this issue and concluded that the existing definitions are adequate to accommodate increasing size of cattle.