Pilot experiment with the aim to reduce salmonella prevalence in pork by logistic slaughter of pigs

A pilot experiment was carried out with the aim to evaluate the possibilities and results of logistic slaughter of pigs (separate slaughter of salmonella-free and salmonella-infected pig herds) under usual circumstances in a Dutch slaughterhouse. During the experiment salmonella-free herds were delivered and slaughtered on Tuesday mornings. Herds delivered on Thursday mornings served as a control group. No significant difference could be found in the number of salmonella-positive carcasses on Tuesdays and Thursdays. This was mainly caused by contamination of carcasses by contaminated slaughter equipment; 80% of all salmonella strains on carcasses were equal to strains isolated from slaughter equipment. If these salmonella strains were not included in the results, logistic slaughter did result in a significantly lower prevalence of salmonella on carcasses on Tuesdays. It was concluded that separate slaughter of salmonella free pig herds can result in a lower salmonella prevalence on carcasses, but only if slaughter hygiene and especially cleaning and disinfection before and during processing will be improved