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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Food Safety and Enteric Pathogens Research » Research » Publications at this Location » Publication #124665
Title: MEASURING SALMONELLA PREVALENCE ON SWINE FARMS AND AT THE ABATTOIR

Author
item Hurd, Howard
item MCKEAN, J - IOWA STATE UNIVERSITY
item ROSTAGNO, M - FEDERAL UNIV OF LAVRAS
item GRIFFITH, R - IOWA STATE UNIVERSITY
item Wesley, Irene

Submitted to: American Association of Swine Veterinarians Annual Meeting
Publication Type: Proceedings
Publication Acceptance Date: 2/27/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Using six herds depopulated during the Accelerated Pseudorabies Eradication Program (APEP), we tested and necropsied almost 600 market pigs. Three days before depopulation, 100 finish pigs on each farm were snared, ear tagged, and 1 g feces was collected for culture. On the day of depopulation, one half of the group was sent to slaughter at a commercial abattoir. After 2-3 hours holding, these pigs were stunned, exsanguinated, and necropsied. The remaining 50 pigs were necropsied on the farm, the next day. The same tissues were collected at the abattoir and on the farm (ileocecal lnn, cecal contents, fecal loops, superficial inguinal lnn). The following results are based on presumptive biochemical tests for Salmonella and serogrouping. The preliminary analysis shows, the estimated average prevalence for all six herds was 3.2% (9/281) using the 1 g antemortem fecal. The estimates from on-farm collected ileocecal lnn and cecal contents were 3.9% and 2.8%, respectively. The average herd prevalence estimate was 8.5%, when combining cecal contents, ileocecal lnn, and postmortem fecal samples. This increase in prevalence is to be expected when an insensitive test is repeated on the same population. When comparing the fecal samples collected at necropsy with cecal contents and ileocecal lnn, there was no agreement on positive samples; kappa statistics were less than one. For pigs necropsied at the abattoir, the estimated average herd prevalence was 40.8% (117/287). These studies suggest that antemortem fecal culture severely underestimates the true Salmonella prevalence.