#02-187

Complete

Date Full Report Received

05/20/2004

Date Abstract Report Received

07/26/2006

Investigation

Institution:
Primary Investigator:

This study represents the first attempt to classify typical Midwestern
production sites for Salmonella spp. sero-prevalence using the Danish classification system. With 1,131 farms represented, this data provides a useful snapshot of Midwestern Salmonella prevalence and can be used as a benchmark for future efforts. The data suggest that Midwestern herds are similar in their distribution with respect to Salmonella sero-prevalence classifications as Danish herds. It also indicates that a significant percentage of farms present a small number of market swine for harvest that have experienced prior Salmonella exposure
This study compared information obtained from production practice questionnaires generated by producer self-administration and by interview. Interview-based applications gave better repeatability and content validity. The main modifications of the current questionnaires should include: (1) clarification of terminology by using interviews as a method of questionnaire delivery and (2) removal of highly correlated questions. When modifying a production practices questionnaire, efforts should be made to clearly capture farm structure differences between on-site and off-site production systems, and how they affect biosecurity responses. Another area for improvement in future questionnaires is the use of common terminology.
The most serious limitation of any questionnaire has not been addressed by this study, and that is the true accuracy or criteria validation. No gold standard exists to compare the responses with on-farm Salmonella exposure, and therefore, the responses from either the self-administered or the interview questionnaire may not accurately reflect true on-farm Salmonella risks.