The Food and Agriculture Organization's Gridded Livestock of the World.

Livestock sector planning, policy development and analysis are frequently hampered by the paucity of reliable and accessible information on the distribution, abundance and use of livestock. In an attempt to redress this shortfall, the Food and Agriculture Organization's Animal Production and Health Division (FAO-AGA) has, in collaboration with the Environmental Research Group Oxford, developed the 'Gridded Livestock of the World' database which provide the first standardised global, sub-national resolution maps of the major agricultural livestock species. These are now freely available for download on the FAO website. The data are produced in Environmental Systems Research Institute grid format for cattle, buffalo, sheep, goats, pigs, chickens and other poultry. The map values are animal densities per square kilometre, at a resolution of 3 minutes of arc (approximately 5 km at the Equator), and are derived from official census and survey data. Reported statistics are then processed using a combination of suitability masking and spatial disaggregation by statistical modelling of livestock densities based on empirical relationships between livestock densities and environmental variables in similar agro-ecological zones. The spatial nature of these livestock data allows a wide array of applications. Livestock distribution data give an estimation of production; they evaluate impact (both of and on livestock) by applying a variety of rates; and they provide the denominator in prevalence and incidence estimates for epidemiological applications, and the host distributions for transmission models.