Location: Meat Safety and Quality
Project Number: 3040-42000-021-013-T
Project Type: Trust Fund Cooperative Agreement
Start Date: Jan 1, 2025
End Date: Apr 1, 2026
Objective:
Objective 1. Compare the abilities of 10-gram pen surface soil, 10-gram fecal pat, and water trough sponge sampling methods for their abilities to detect and quantify diverse Salmonella populations in beef cattle feedyards. (March 2025 – September 2025)
Objective 2. Compare the abilities of BAX SalQuant, MPN, and Poisson Limit One Tube laboratory methods for quantifying Salmonella in beef cattle feedyards. (March 2025 – September 2025)
Objective 3. Using the optimal sampling and laboratory methods identified in objectives 1 & 2, characterize measure Salmonella levels in 4 feedyards for 1 year. (October 2025 – September 2026). Management practices (dietary composition, antibiotic use, cattle origin, backgrounding etc.) and environment (pen surface soil chemistry, weather)
Objective 4. Combining the Salmonella occurrence data, management data and environmental data collected in Objective 4 identify the relative contributions of management and environmental factors to Salmonella occurrence.
Approach:
During March 2025, 40 samples will be taken from each of 4 feedyards with a history of high Salmonella levels. The feedyard with the highest level will be the selected as the study feedyard for Objectives 1 and 2. On three occasions beginning in April 2025 48 pens will be sampled by each of three methods 10-gram pen surface soil, 10-gram fecal pat, and water trough sponge. Salmonella will be quantified in each of these 432 samples by three laboratory methods: BAX SalQuant, MPN, and Poisson Limit One Tube. Salmonella diversity will be measured by a multiplex PCR for 8 genes associated with high human pathogenicity (HPS assay) and Deep Serotyping. Objective 1 and 2 sampling will occur during April, May, and June to allow time for re-sampling during July, August, and September if Salmonella levels were not sufficiently high.
Beginning in October 2025 4 feedyards (2 known to have high Salmonella levels and 2 known to have low Salmonella levels) will have up to 48 pens sampled once per quarter for one year using the optimal sample and laboratory methods identified in objectives 1 and 2. 4 yards * 48 pen * 4 seasons = 768 samples. Management practices (dietary composition, antibiotic use, cattle origin, backgrounding etc.) and environment (pen surface soil chemistry, weather) will be collected for each feedyard. The same pens will be sampled during each season.
Following the completion of Objective 3 data will be analyzed to determine identify the relative contributions of management and environmental factors to Salmonella occurrence in beef cattle feedyards.