Fact Sheet No. 21: Grazing Management Terms

Allowable use. (1) the degree of utilization considered desirable and attainable on various parts of a ranch or allotment considering the present nature and condition of the resource, management objectives, and levels of management. (2) The amount of forage planned to be used to accelerate range improvement.

Animal-Unit (AU). Considered to be one mature cow approximately 1,000 pounds, either dry or with calf up to 6 months of age, or their equivalent, based on a standardized amount of forage consumed.

Animal-Unit month (AUM). The amount of dry forage required by one animal unit for one month based on a forage allowance of 26 pounds per day. The term AUM is commonly used in three ways: (a) stocking rate, as in "X acres per AUM" (b) Forage allocations, as in "X AUMs in allotment A" (c) Utilization, as in "X AUMs taken from Unit B".

Available Forage. That portion of the forage production that is accessible for use by a specified kind or class of grazing animal.

Carrying capacity. The maximum stocking rate possible which is consistent with maintaining or improving vegetation or related resources. It may very from year to year on the same area due to fluctuating forage production.

Class of animal. Description of age and/or sex group for a particular kind of animal. Example, cow, calf, yearling, ewe, doe, fawn, etc.

Continuous grazing. The grazing of a specific unit by livestock throughout a year or for that part of the year during which grazing is feasible. The term is not necessarily synonymous with yearlong grazing, since seasonal grazing may be involved.

Deferment. Delay of livestock grazing on an area for an adequate period of time to provide for plant reproduction, establishment of new plants, or restoration of vigor of existing plants.

Deferred Grazing. The use of deferment in grazing management of a management unit, but not in a systematic rotation of the deferment among pastures.

Exclosure. An area fenced to exclude animals.

Exclusion. Range that is closed to grazing by livestock.

Forage Allocation. The planning process or act of apportioning available forage among various kinds of animals, e.g., elk and cattle

Grazing Distribution. Dispersion of livestock grazing within a management unit or area.

Grazing Fee. A charge, usually on a monthly basis, for grazing use by a given kind of animal.

Grazing, Heavy. A comparative term which indicates that the stocking rate of a pasture is relatively greater than that of other pastures. Often erroneously used to mean overuse.

Grazing Management Plan. A program of action designed to secure the best practicable use of the forage resources with grazing or browsing animals.

Grazing Period. The length of time that animals are allowed to graze on a specific area.

Grazing Pressure. An animal to forage relationship measured in terms of animal units per unit weight of forage at any instant.

Grazing Season. (1) On public lands, an established period for which grazing permits are issued. May be established on private land in a grazing management plan. (2) The time interval when animals are allowed to utilize a certain area.

Grazing System. A specialization of grazing management which defines the periods of grazing and non-grazing. Descriptive common names may be used; however, the first usage of a grazing system name in a publication should be followed by a description using a standard format. This format should consist of at least the following: The number of pastures (or units) number of herds, length of grazing periods, length of non-grazing periods for any given unit in the system followed by an abbreviation of the unit of time used. See deferred grazing, deferred-rotation, restoration, and short duration grazing.

Herbage Allowance. Weight of forage available per unit animal on the land at any instant.

Holistic Resource Management. Holistic Resource Management (HRM) is a practical, goal-oriented approach to the management of the ecosystem including the human, financial and biological resources on farms, ranches, public and tribal lands, as well as national parks, vital water catchments, and other areas. HRM entails the use of a management model which incorporates a holistic view of land, people, and dollars.

Kind of Animal. An animal species or species group such as sheep, cattle, goats, deer, horses, elk, antelope, etc.

Light grazing. A comparative term which indicates that the stocking rate of one pasture is relatively less than that of other pastures. Often erroneously used to mean proper use.

Non-selective grazing. Utilization of forage by grazing animals in such a way that all forage species and plants are grazed to a comparable degree. It is generally achieved by using a high stocking density for a short grazing period.

Overgrazing. Continued heavy grazing which exceeds the recovery capacity of the community and creates a deteriorated range.

Overstocking. Placing a number of animals on a given area that will result in overuse if continued to the end of the planned grazing period.

Overuse. Utilizing an excessive amount of the current year's growth which, if continued, will result in range deterioration.

Proper grazing. The act of continuously obtaining proper use.

Proper use. A degree of utilization of current years growth which, if continued, will achieve management objectives and maintain or improve the long term productivity of the site. Proper use varies with time and systems of grazing.

Proper use factor. An index to the grazing use that may be made of a specific forage species, based on a system of range management that will maintain the economically important forage species, or achieve other management objectives such as maintenance of watersheds, recreation values, etc.

Range condition. (a) A generic term relating to present status of a unit of range in terms of specific values or potentials. Specific values or potentials values or potentials must be stated. (b) Some agencies define range condition as follows: The present state of vegetation of a range site in relation to the climax (natural potential) plant community for that site. It is an expression of the relative degree to which the kinds, proportions, and amounts of plants in a plant community resemble that of the climax plant community for the site.

Range readiness. The defined stage of plant growth at which grazing may begin under a specific management plan without permanent damage to vegetation or soil. Usually applies to seasonal change.

Rest. Leaving an area ungrazed, thereby foregoing grazing of one forage crop. Normally rest implies absence of grazing for a full growing season or during a critical portion of plant development, i.e., seed production.

Rest period. A time period of no grazing including as part of a grazing system.

Rest-rotation. A grazing management scheme in which rest periods for individual pastures, paddocks, of grazing units, generally for the full growing season, are incorporated in to a grazing rotation.

Riparian zone. The banks and adjacent areas of water bodies, water courses, seeps, and springs whose waters provide soil moister sufficiently in excess of that otherwise available locally so as to provide a more moist habitat than that of contiguous flood plains and uplands.

Rotational grazing. A grazing scheme where animals are moved from one grazing unit (paddock) in the same group of grazing units to another without regard to specific graze rest periods or levels of plant defoliation.

Sacrifice area. A portion of the range, irrespective of site, that is unavoidably overgrazed to obtain efficient overall use of the management area.

Seasonal distribution. (1) The progressive grazing in a sequence of moves from one pan of a range to another as vegetation develops. (2) The normal occurrence of precipitation at different periods of the year.

Seasonal grazing. Grazing restricted to a specific season.

Seasonal use. (1) Synonymous with seasonal grazing. (2) Seasonal preference of certain plant species by animal.

Short-duration grazing. Grazing management whereby relatively short periods (days) of grazing and associated non-grazing are applied to range or pasture units. Periods of grazing and non grazing are based upon plant growth characteristics. Short duration grazing has nothing to do with intensity of grazing use.

Stocking density. The relationship between number of animals and area of land at any instant of time. It may be expressed as animal units per acre, animal units per section, or AU/ha.

Stocking plan. The number and kind of livestock assigned to one or more given management areas or units for a specified period.

Stocking rate. The number of specific kinds and classes of animals grazing or utilizing a unit of land for a specified time period. May be expressed as animal unit months or animal unit days per acre, hectare, or section, or the reciprocal (area of land/animal unit month or day). When dual use is practiced (e.g., cattle and sheep), stocking rate is often expressed as animal unit months/unit of land or the reciprocal.

Substitution ratio. Number of animals or animal-units of one kind of class which can be substituted for another kind of class to meet a specified management objective

Trampling. Treading underfoot.; The damage to plants or soil brought about by movements or congestion of animals.

Undergrazing. The act of continued underuse.

Usable forage. That portion of the forage that can be grazed without permanent damage to the forage plant species or the other basics resources; may very with season or use, plant species and associated plant species.

Use/utilization. (1) The proportion of current year's forage production that is consumed or destroyed by grazing animals. May refer either to a single species or the vegetation as a whole. Syn., degree of use. (2) Utilization of range for a purpose such as grazing, bedding shelter, trailing, watering, watershed, recreation, forestry, etc.

Winter range. Range that is grazing during the winter months.

Wolf plant. (1) An individual plant that is generally considered palatable but is not grazed by livestock. (2) An isolated plant growing to extraordinary size, usually from lack of competition or utilization.

Yearlong grazing. Continuous grazing for a calender year.

Yearlong range. Range that is or can be, grazed yearlong.

A Glossary of Terms Used in Range Management. Third edition, 1991. Compiled and edited by the Glossary Revision Special Committee, Publications Committee, Society for Range Management, 1839 York Street, Denver, CO 80206.