Farming conditions and practices linked to Salmonella prevalence in slaughter pigs

This study aimed at identifying farming conditions and practices linked to salmonella prevalence in slaughter pigs, both in 208 breeder-finisher and in 109 only-finisher herds. Salmonella serological status was determined in each farm on 42 meat juice samples from three slaughter batches. Analysis was performed using the IDEXX kit. Data considered as possible risk factors for salmonella prevalence were collected at the farm level, using a specific questionnaire. Statistical analysis relies on logistic regression models defined for both types of pig farms. Global models were designed, using all the available data. To maximise the number of useable individual farm results (due to missing data), focused models concerning either feeding conditions, health or bio-safety, were also performed.In breeder-finisher herds, farming conditions which appeared to be related to salmonella prevalence were mainly pig health farm status (i.e. clinical events in quarantine, PRRS or PMWS clinical signs at the post-weaning stage) and veterinary treatments (e.g. antiparasite protocol in quarantine, antibiotics on farrowing sows, health protocols at the post-weaning stage, number of antibiotics treatments during the fattening phase). Liquid feeding for pregnant sows and fattening pigs was assumed to have a preventive effect and proper to reduce salmonella prevalence, as well as drinking pipes in post-weaning. Good practices regarding both pig pre-loading and loading conditions and adapted cleaning and disinfection protocols were also positive factors.In only fattening farms, only two farming conditions were identified: the number of breeding units supplying piglets and the number of antibiotics treatments during the fattening stage.