Compare the microbiology of eggs obtained from caged Leghorn hens and cage-free floor housed Leghorn hens with both naturally contaminated and artificially inoculated environments.
Approach: Day of age Leghorn pullets will be obtained and reared in a confinement rearing facility set up to industry standards until the birds reach sexual maturity. At this time, a confinement housing facility would be set up to simulate a commercial Leghorn setting where the hens are housed in cages versus a confinement rearing facility where Leghorn hens are housed on the floor and eggs collected from nest boxes. To test the microbiology of the eggs from the two laying areas, an assortment of microbiological analyses (i.e. total aerobic plate count, Enterobacteriaceae count, E. coli count, Campylobacter, and Salmonella) of the eggs from both groups will be performed. In addition, another set of experiments will be conducted where the Leghorn hens are inoculated and colonized with a Naladixic acid resistant Salmonella and analysis of the eggs conducted.