Control of Salmonella Environmental Contamination during Pig Transport and Lairage: a Realistic Project?

This study aims at investigating Salmonella environmental contamination of trucks and lairage pens and evaluating the efficiency of an improved cleaning and disinfection protocol to reduce Salmonella environmental contamination. During four days, the lairage of two French pig slaughterhouses were sampled twice a day when pigs were present and once at the end of the week after the cleaning protocol. In parallel, six trucks per day were randomly selected and sampled at their arrival and after the cleaning procedure. The samples consisted of floor surface swabbing. Salmonella occurrence, level of contamination and serotypes were determined. The efficiency of different cleaning and disinfection procedures on the presence of Salmonella was also estimated. Salmonella was isolated in 97.7% of the lairage samples when pigs were present (contamination levels >104UFC/m 2 ) and in 65% of the truck samples (contamination levels from <10 to >104UFC/m 2 ). An improved cleaning and disinfection procedure reduced efficiently the occurrence and the level of contamination in the trucks (almost 100%) compared to a simple wash with cold water (no effect), more partially in the lairage. This study showed the importance of a good cleaning and disinfection protocol to decrease the level of contamination or eliminate the bacteria in the trucks used for the transport of pigs.