Abstract #W95

# W95
Identifying sources of Salmonella contamination in animal feed and pet food facilities.
Andrea M. Jeffrey*1, Cassandra K. Jones1, Greg Aldrich1, Anne R. Huss1, Carl Knueven2, 1Kansas State University, Manhattan, KS, 2Jones-Hamilton, Walbridge, OH.

Salmonella is a potential biological hazard in animal food, and may contaminate livestock feed and pet food through cross contamination at manufacturing facilities. The FDA has evaluated Salmonella concentrations in classes of feed ingredients, but has not evaluated pathogen concentrations based on location throughout a facility. The objective of this experiment was to investigate sources of Salmonella contamination from various equipment and environmental locations in 2 livestock feed manufacturing plants and 2 pet food manufacturing plants on a specific sampling day. Up to 40 environmental swab samples were collected at each facility using sterile, prepackaged swab vials containing buffered peptone water. Samples were collected from a variety of equipment and structural surfaces, including concrete, dust, plastic, rubber, and broom bristles and analyzed for qualitative Salmonella determination as described by FDA’s Bacteriological Analytical Manual. Data were categorized by facility (1 to 4), type (equipment or structural), and surface (concrete, metal, plastic, rubber, or dust) and analyzed using the GLIMMIX procedure of SAS. There were no interactions, so all were removed from the model (P > 0.05). There were no differences in Salmonella-positive samples among facilities, but facility 1, a livestock feed manufacturer, doubled the locations testing positive for Salmonella as compared with the other 3 facilities (P = 0.11; average positive-Salmonella concentration of 44.1, 20.1, 19.0, and 20.1% for facilities 1, 2, 3, and 4, respectively). There were no differences in percentage of Salmonella samples testing positive based on location of swab (P = 0.57; average Salmonella concentration of 22.9 and 28.7% for equipment and structural, respectively). Finally, there was a tendency for rubber and concrete to have greater Salmonella-positive samples than plastic, dust, or metal (P = 0.10; 40.9, 35.2, 24.4, 20.4, and 8.2%, respectfully). With these results in mind, it may be important to consider the types of surfaces present and the appropriate sanitation to best control Salmonella in livestock and pet food manufacturing facilities to prevent cross-contamination into animal food.

Key Words: Salmonella, animal feed, pet food