There is a paucity of data explaining the persistence ofSalmonella serovars on swine farms. In this study, we evaluated 900 pigs from 18 cohorts of finisher swine over a 3.5 year period in one production company to understand the distribution and persistence ofSalmonella serovars on swine farms and to identify risk factors associated with persistence ofSalmonella serovars in swine. Based on the results of this study, the duration ofSalmonella shedding in pigs is associated with the Salmonella status of the nursery of origin (more positive samples from the nursery, the longer the duration of shedding), infection at a younger age (pigs first detected as positive at 10 weeks of age shed Salmonella longer than pigs 12 week of age or older at first positiveSalmonella fecal sample) Salmonella serovar (S. Agona was shed for a longer duration) and the number of treatments in the group of pigs from which the pig originates (above average treatment rate decreased the duration of Salmonella shedding in swine).