Resource information
Extensive grazing is the predominant form of land use on at least a quarter of the world’s land surface, in which livestock are raised on food that comes mainly from rangelands. The term livestock includes both domesticated animals such as cattle, sheep, goats, camels, horses, llamas and alpacas, and a broad range of wild animals kept for meat or game viewing. It is estimated that tropical grasslands alone cover 18 million square kilometres, where the natural vegetation is used by mobile animals requiring forage and water throughout the year. Extensive grazing differs from crop or forestry production, in which the produce remains in situ whilst growing. Extensive grazing and arable agriculture often either compete for limited land or coexist in symbiosis. Its very size and mobile nature ensure that it is a most variable kind of land use, not conducive to being neatly parcelled into specific units of land occupied by growing crops, or into growing periods. Evaluation for extensive grazing, unlike that for cropping or forestry, must take into account the production of both grazing forage, termed primary production, and the livestock that feed on this forage, termed secondary production. Extensive grazing also differs from intensive grazing, in which the animal feed comes mainly from artificial, seeded pastures and not from unimproved rangeland. Rangelands are tracts of land used for grazing by domestic livestock or wildlife, where natural vegetation is the main forage resource (adapted from Gils 1984). They may be used for ranching, where animals graze on private and usually fenced land, or for three other systems of extensive grazing: nomadic pastoralism, transhumance or sedentary pastoralism. In the latter case the rangelands may be part of an agro-pastoral land use system.