Spreading of slurry infected with multi-resistant Salmonella Typhimurium DT104 (MRDT104) on arable land might constitute a risk of transmission to wildlife. To estimate survival time on farmland, we modeled the bacterial decay based on Escherichia coli data from a plot study carried out in spring 2002 in Denmark. Time until undetectable levels were modeled under different scenarios: 1) E. coli in swine slurry, 2) Salmonella in slurry from clinically infected swineherds, and 3) MRDT104 in slurry from sub-clinically infected swineherds. A log-linear model extended with time2 and time3 was used to describe bacterial decay. For scenarios 2 and 3, we assumed that the level of bacteria in the slurry would be log 4.0 cfu/g and log 3.4 cfu/g, respectively, and a similar effect of spreading and decimation to that of E. coli. Hereby, it was estimated that Salmonella counts fell below detectable levels after 10 and 5 days, respectively.