Assessment of the adequacy of available spatial data of the demographics of swine populations in Minnesota.

Reliable data on the demographics of animal populations are essential for effective planning and execution of disease control programmes. To document the spatial distribution of different swine populations in Minnesota, the authors evaluated four sources of data from separate entities that maintain data independently and for different purposes. Although the total numbers of swine sites (aggregated at the county level) were significantly correlated among datasets, analysis of spatial clustering patterns demonstrated regional biases among the datasets. We used current, field verified data of farm locations in two counties to identify and quantify inaccuracies in two databases recording individual farm locations. The proportion of omitted or erroneous farm sites and the magnitude of positional inaccuracies were sufficient to limit the utility of available data for analytic purposes or for disease control efforts. There is a clear need for more current and accurate demographic data to underpin industry or government initiatives to control swine disease in Minnesota. Current efforts under the National Animal Identification System may address this concern.