Location: Food and Feed Safety Research
Project Number: 3091-32000-037-012-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jun 1, 2025
End Date: May 31, 2027
Objective:
Determine if a USDA developed Competitive Exclusion culture can reduce Salmonella in poultry and poultry products.
Approach:
1. Leghorn layers will be obtained from a local commercial facility at 50+ weeks of age and housed at the USDA-ARS facility with one layer per pen. Hens will be provided free access to water and a balanced unmedicated mash layer feed ration. Fecal samples will be collected from the hens to verify the Salmonella status. Hens that test positive for Salmonella upon entry to the facilities will be removed from the study. In addition, hens that were housed in the cages, on either side of the positive hen's cage, will also be removed from the study. Hens will be allowed to acclimate for one week and then randomly assigned to two treatment groups of 36 birds per treatment. At Day 1, Competitive Exclusion cultures added to feed will be provided to the hens in group two, per National Research Council (NPC) specifications. On Day 3, all hens in each group will be orally challenged with 1 mL of inoculum containing 1 x 107 Colony Forming Units (CFU) of a Salmonella identified to cause food-born illness in humans. Eggs will be collected from layers three days per week for 35 days post inoculation, cultured, and analyzed for Salmonella prevalence on the shell, as well as internally.
2. Broiler chicks or turkey poults will be obtained from a commercial hatchery at day-of-hatch and housed at the USDA-ARS facility with 20 birds per pen. Birds will be provided free access to water and a balanced unmedicated starter feed ration for the appropriate species. Fecal samples will be collected from the birds to verify the Salmonella status. Birds that test positive for Salmonella upon entry to the facilities will be removed from the study. At Day 1, Competitive Exclusion cultures or their components (postbiotics) will be added to feed and will be provided to the birds in group two, per National Research Council (NPC) specifications. On Day 3, all birds in each group will be orally challenged with 1 mL of inoculum containing 1 x 107 Colony Forming Units (CFU) of a Salmonella identified to cause food-born illness in humans. Feces and ceca will be collected from birds on 35 days post inoculation, cultured, and analyzed for Salmonella prevalence.