Risk factors associated with Salmonella prevalence in breeding&fattening and in only-fattening herds

The aim of this study is to assess the risk factors linked to salmonella prevalence of slaughter pigs, both in breeding-fattening and in only-fattening herds. Salmonella serological status is determined in 123 farms, of which 29 only-fattening herds. Each farm status is based on 40 to 60 meat juice samples involving 3 to 8 slaughter pigs batches. Sample analysis is carried out by using the IDEXX commercial kit with a 10% OD cut-off value. On farm inquiries are made to collect information items presumed as being possible risk factors predictors. Statistical analysis is based on a logistic regression model applied to the two types of pig farms concerned.Sow batch mixing in farrowing stage and failure in all in - all out practice in fattening rooms are associated with higher seroprevalence as far as the lack in quarantine of gilt acclimatization to the herd microbiological digestive status or absence of antiparasite protocol. Two identified risk factors are associated to hygiene level in farrowing rooms: diarrhea occurrence and a non systematic antibiotic treatment on young piglets. On the opposite, high hygienic quality of water and the strict observance of cleaning and disinfecting protocol (ie systematically disinfecting and observing a sufficient break duration between two subsequent batches in post-weaning rooms; using automatic soaking and detergent in fattening rooms) are linked to lower prevalence levels. The number of fattening pigs per pen is also associated with positive salmonella status.