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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 #149072
Title: THE ROLE OF DISINFECTION IN THE CONTROL OF SALMONELLA IN SWINE LAIRAGE PENS (4TH INT CONF ON EMERGING ZOONOSES, AMES, IA, 9/18-21/03)

Author
item SCHMIDT, P - IOWA STATE UNIV
item O'CONNOR, A - IOWA STATE UNIV
item MCKEAN, J - IOWA STATE UNIV
item Hurd, Howard

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/18/2003
Publication Date: 9/18/2003
Citation: SCHMIDT, P.L., O'CONNOR, A.M., MCKEAN, J.D., HURD, H.S. THE ROLE OF DISINFECTION IN THE CONTROL OF SALMONELLA IN SWINE LAIRAGE PENS. INTERNATIONAL CONFERENCE ON EMERGING ZOONOSES. 2003. ABSTRACT p. 27.

Interpretive Summary:

Technical Abstract: Several studies suggest market hogs slaughtered on farm tend to have lower rates of Salmonella recovery than those slaughtered at the abattoir after routine holding. If the lairage represents a location where swine are exposed to Salmonella then interventions that reduce exposure in the lairage may limit the number of Salmonella positive swine entering the post-harvest production process. The objective of this field trial was to determine the ability of disinfection to reduce Salmonella levels in lairage pens and its impact of Salmonella recovery rates in swine. Three replicates of the study were conducted in a large commercial abattoir. In each replicate, an untreated control pen represented the environment pigs would be exposed to at the study abattoir. Another pen was cleaned using an alkaline chloride detergent followed by disinfection using a hydrogen peroxide/peracetic acid sanitizer. One hundred-eighty pigs were sorted off the transport trailer and groups of five were randomly allocated to the treated or untreated pens. After the pigs had been held for 2-4 hours the two groups were slaughtered. Forty swabs were collected from the pen floor: 1) from the control pen, 2) from the treated pen prior to disinfection, and 3) from the treated pen after disinfection. Cecal contents, fecal contents and ileo-cecal lymph nodes were collected from 45 swine from each pen. These samples were cultured for recovery of Salmonella. Two data analyses were conducted: one tested the null hypothesis that disinfection did not reduce the amount of Salmonella recoverable from the pen. The second analysis tested the null hypothesis that percentage of animals from which Salmonella could be recovered did not differ between the disinfected and control pens. In all replicates the proportion of Salmonella recoverable from the pen floor after disinfection was significantly less than before cleaning and disinfection (before prevalence 20-100%, after prevalence 5-15%). No difference in Salmonella existed between treatment and control groups in the 1st replicate. However, preliminary results in the 2nd and 3rd replicates indicate Salmonella was more likely to be recovered in tissues from swine held in disinfected pens (p<0.05). Completion of further analysis of recovered Salmonella, including antibiogram and serotype data, as well as additional replicates may provide insight into the high prevalence of Salmonella in swine exposed to a cleaned and disinfected environment.