Danish finishing herds are routinely screened for antibodies to Salmonella in random samples of meat juice from slaughter pigs. The herds are categorized by the seroprevalence of samples from the preceding three months into three infection levels (1, 2 and 3). Herds are allocated to level 3 ("Salmonella high risk" herds) at seroprevalences exceeding 33-50% depending on herd size (larger herds lower limit) (Mousing et al., in press).