Livestock Unit

The Livestock Unit, LU or LSU is a measure of livestock grazing in agriculture. One Livestock Unit is usually defined as the grazing equivalent of one adult dairy cow. Many different schemes exist, giving various values to the grazing effect of different types of animal.

Use

LUs are used for assessing the overall effect on grazing land of different types of animals (or of mixtures of animals), expressed either as a total for a whole field or farm, or as LUs per hectare (ha) or acre. For example, using UK government LUs a particular convert|10|ha|acre|abbr=on pasture field might be able to support 15 adult cattle, 25 horses or 100 sheep; each of these would be regarded as being 15 LUs, or 1.5 LUs per hectare (about 0.6 LUs per acre).

Different species (and breeds) of livestock do not all graze in the same way, and this is also taken into account when deciding the appropriate number of LUs for grazing land. For example, horses naturally graze unevenly, eating short grass areas first and only grazing longer turf if there is insufficient short grass; in contrast, cattle graze longer grass preferentially, tending to produce a uniform sward. As these grazing styles are complementary, a pasture may therefore support slightly more LUs of mixed species than of each species separately. Another consequence of different grazing styles is variation between species in the number of LUs that can lead to overgrazing – for example, horses may overgraze the short parts of a pasture even when taller grass is still available.

Livestock Units are used by many governments to measure and control the intensity of farming. For example, until 2004 the UK Government had an extensification scheme which paid additional subsidy to farmers who kept their livestock at less than an average of 1.4 LUs per hectare."Cattle Scheme Literature: Notes for Guidance 2003", UK Rural Payments Agency, 2003 (pp 11 & 25)]

chemes

Although different schemes have similar aims, they vary in complexity and detail. For example, some schemes give no value to a young calf, but an additional value to a cow together with her calf at foot. Some give values to different-sized animals of the same species, or different values to the same species in different regions.

Different schemes may be more similar than they appear at first sight – for example, for cattle in mixed-age herds the UK government scheme and the Nix scheme often give almost identical LU figures.

The following is a summary of some schemes in common use, using the most closely comparable categories:

References