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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Meat Safety and Quality » Research » Research Project #445120

Research Project: Understanding the Impact of the Farm and Lairage Environments on Salmonella Contamination in Market Hogs

Location: Meat Safety and Quality

Project Number: 3040-42000-020-017-T
Project Type: Trust Fund Cooperative Agreement

Start Date: Aug 15, 2023
End Date: Feb 14, 2025

Determine which samples represents the best opportunity for determining Salmonella load and risk in a market hog processing facility. Assessing Salmonella contamination along the swine production chain is required to determine specific points in the production system that increase the risk of carcass contamination, and if particular sample types can be predictive of Salmonella contamination in pork products.

Groups of market hogs, and their environments, will be sampled on-farm (from multiple farms) and at lairage to detect and enumerate Salmonella from ropes, boot swabs, pen floor swabs, fecal samples, waterers, etc. The same pens of market hogs sampled pre-harvest will be followed to the abattoir to collect lairage, harvest, and post-harvest samples. At the abattoir, the amount of time each pen spends in lairage will be recorded, and categorized as follows (minutes): 0-90, 91-180, 181-270, and >270. Carcasses will be swab sampled pre- and post-evisceration, pre-chilling and post-chilling. Mesenteric, tracheobronchial, subiliac, and superficial inguinal lymph nodes (LNs) will also be collected. Fat and fascia will be trimmed from LNs, and LNs will then be weighed, surface sterilized with a brief boiling step, and pulverized. Salmonella will be detected and enumerated from each sample as using culture and molecular methods. ARS will assist in Salmonella culture and ARS will determine the serotype and virulence genotype of isolates recovered from each positive sample.