THE EFFECT OF SOURCE HERD AND ABATTOIR FACTORS ON PIG CARCASE SALMONELLA CONTAMINATION EVALUATED BY MULTILEVEL MODELLING

摘要

In Denmark, a Surveillance-and-Control Programme for Salmonella in pigs has been in place for several years. This study investigated factors associated with Salmonella pig carcase prevalence, measured in pools of five carcase swab samples. A total of20,128 pooled carcase swabs collected in 22 Danish abattoirs, from 2002 to 2008, were included in a multilevel logistic regression model.Study results indicate that the probability of Salmonella positive carcases is mainly influenced by weekday, estimated daily number of Salmonella seropositive pigs delivered to slaughter and average Salmonella seroprevalence of the source herds that delivered each of the five pigs contributing to the pool that was sampled on the day of slaughter. Model results suggest that risk-mitigation actions at the abattoir such as improved practices including hygiene and staff training, logistic slaughter and decontamination might result in a further reduction in carcase pool Salmonella prevalence.