2.2 Trade description
Premises that moved at least once during the study period were included as nodes in the network; premises for which no movements were recorded were assumed to be inactive. In order to represent the spatial distribution of premises, the number of premises was grouped by geolocation across a ~3km2 grid (see figure 1). The production type of each premises was classified according to the records provided by the official surveillance veterinary service. Eight type of premises were classified: Finishers (n = 7119), Breeding-farms (n = 2255), Non-commercial or backyard farms (n= 2055), Nursery farms (n = 1398), Wean-to-finisher & mixed farms ( n= 447), Slaughterhouses (n=189), Certified-Swine-Breeder-Farms (n = 138), and others premises (n=111).