and purchase of animals. Further research has to be done on
the effect of the acid tolerance response as inconsistent results are
often obtained in studies focusing on administration of organic
acids. The development of biofilms and the interaction between Salmonella
and protozoa needs to be further investigated as these may
be partially responsible for unsatisfactory results following cleaning
and disinfection. Vaccination against S. Typhimurium is possible in
sows and piglets but in the current monitoring programs no distinction
can be made between naturally infected and vaccinated animals.
In order to efficiently reduce Salmonella prevalence at the
primary production level, a combination of herd-specific control
measures should be implemented. Fasting procedures before
slaughter, animal handling during loading and transport and lairage
conditions should be also critically evaluated.