Salmonella Epidemiology in Finisher Pigs and the Effect of Two Treatment Strategies on the Occurrence of Salmonella

This thesis is a collection of three studies on the distribution of Salmonella in grower-finisher pigs, the effect of improved hygiene on the shedding of Salmonella in finisher pigs and the effect of water acidification on the shedding of Salmonella in nursery pigs. Twenty herds were tested at the pen-level at various stages through the grow-finish stage for the presence of Salmonella. It was found that the pens occupied by younger pigs were more likely to have Salmonella. A Salmonella positive farm was chosen for intervention to reduce Salmonella with improved hygiene in the finisher barn. Washing could not be shown to reduce the shedding of Salmonella in this barn but did impact the occurrence of diarrhea in the pens. In the same Salmonella positive herd water acidification was introduced to some of the nursery pens. Acidification of water could also not be shown to reduce Salmonella in the nursery.