Risk factors for the herd-level bacteriologic prevalence of Salmonella in Belgian slaughter pigs
Nollet, N Maes, D De Zutter, L Duchateau, L Houf, K Huysmans, K Imberechts, H Geers, Rony de Kruif, A Van Hoof, J #
Elsevier science bv
Preventive veterinary medicine vol:65 issue:1-2 pages:63-75
Herd-level risk factors for salmonellosis in pigs were investigated in a cross-sectional study on 62 Belgian farrow-to-finish pig herds belonging to one slaughterhouse cooperative. Data concerning housing and ventilation, management, hygiene, biosecurity, production parameters, feeding, disease control and transport to the slaughterhouse were collected during a herd visit by means of a questionnaire. The percentage of positive animals in a slaughterhouse delivery, as determined by qualitative Salmonella isolation in the mesenteric lymph nodes taken from 30 slaughter pigs, was the outcome variable. All samples were taken in 4 different slaughterhouses. Variables first were submitted to a univariable analysis using a logistic mixed regression model, with herd as random effect. Variables which were related to the Salmonella prevalence (P < 0.05) were analysed further in a multivariable model. The clustering of Salmonella infection within a pen also was studied in a generalised mixed model with pen as random effect. Salmonella isolates were identified by serotype.