#16-120

Complete

Date Full Report Received

10/04/2018

Date Abstract Report Received

10/04/2018

Investigation

Institution:
Primary Investigator:
Co-Investigators: Catherine Cutter, Edward Dudley

The objective of this research was to estimate the degree to which lymph nodes serve as a harborage area for Salmonella in both market hogs and sows, and the frequency at which positive results are potentially impacted by carcass chilling method. Sampling was conducted at twelve (n = 12) USDA inspected establishments that slaughter swine in the Northern region. This data was combined with research conducted by Texas A&M University (n = 9) in order to determine the National prevalence by geographic region, northern (Penn State) or southern (Texas A&M) region, from pork carcasses at slaughter facilities. At each of the 12 establishments, left and right pairs of superficial inguinal lymph nodes (n = 25 pairs) were extracted from chilled carcasses (except sow operations) from the previous slaughter day and pooled by animal (n = 300 (Northern establishments); n = 207 (Southern establishments); N = 507 Nationwide). Lymph nodes were identified and shipped via overnight carrier for determination of Salmonella prevalence. Prevalence data for Salmonella was separated for market hogs (6.4% positive) and sows (37% positive). The chilling method (conventional – 20% positive, other – 2.7% positive, or blast – 1.3% positive) for market hog samples was also evaluated. Results from this research would suggest that production stage (sow vs market hog) and chilling type are significant factors (P < 0.05) affecting Salmonella prevalence. Chill method (conventional vs blast and other) was also significant (P < 0.017) when compared to samples from Southern establishments, suggesting that cooling capacity is critical, regardless of initial prevalence.