Location: Food and Feed Safety Research
Project Number: 3091-32000-035-04-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2015
End Date: Aug 31, 2020
To feed probiotic to Salmonella inoculated egg laying hens daily in order to determine Salmonella on the egg shell surface and internal contents.
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 tested positive and hens on both sides of the positive hen will be removed from the study. Hens will be allowed to acclimate for 1 week and then randomly assigned to 2 treatment groups of 36 birds per treatment. Probiotics will be provided to the hens in group two in the feed, per NPC specifications, at Day 1. On Day 3, all hens in each group will be challenged orally with 1 mL of inoculum containing 1 x 107 CFU of NO and NA-resistant Salmonella Enteritidis. Eggs will be collected from layers 3 days per week for 35 days post inoculation, cultured, and analyzed for Salmonella prevalence on the shell, as well as internally.