AimsTo assess the efficacy of a -galactomannan oligosaccharide (ss-GMOS) for the control of Salmonella infection in fattening pigs. Methods and ResultsThree different doses (05, 3 and 2kg ss-GMOS per ton of feed) were used during the entire period of growing in three similar and independent field trials carried out in a small fattening unit (approximate to 100 pigs). Treatment was randomly assigned to half of the pens. Individual serum samples (20-25per group) were collected at different times during the fattening period and a similar number of faecal samples during the fattening period and at slaughter. In addition, mesenteric lymph nodes were collected at slaughter. Herdcheck((R)) Swine Salmonella ELISA was used for serological analyses, the ISO 6579:2002/Amd 1:2007 for bacteriology and the PFGE for molecular characterization of Salmonella strains. The addition of 2kgt(-1) of ss-GMOS to the pig diet during the entire fattening period was associated with a reduction in Salmonella prevalence, shedding and seroconversion. ConclusionsFeed supplementation with ss-GMOS may be a useful complementary tool for the control of salmonellosis in fattening pigs. Significance and Impact of the Study ss-GMOS may be a complementary way of reducing Salmonella shedding and infection in fattening pigs.