1. Assess the impact of dietary regimens, housing systems, and different chicken genetic lines on Salmonella (S.) infections of hens, Salmonella contamination of the production environment and eggs, and physical and functional egg quality. 1.a. Holistic comparison of genetic strains in commercial cage-free aviary housing. 1.b. Compare Salmonella shedding and microbial quality of eggs and environment in commercial-style conventional cage, enriched colony cage, enrichable colony cage, cage-free, and free range systems for various genetic strains of laying hens. 1.c. Assess the susceptibility of defined genetic lines of laying hens to infection with S. Enteritidis when housed in different cage-based production systems. 2. Assess the effects of key management practices using experimental and field models of different housing systems on hen health, microbial ecology of foodborne bacteria, and antimicrobial resistance associated with egg contamination. 2.a. Assess the effects of different stocking densities on S. Enteritidis infections in laying hens housed in enriched colony cages. 2.b. Assess the effects of different cage-based housing systems on infections of laying hens with Salmonella serotypes (other than Enteritidis) which are significantly associated with egg contamination. 2.c. Determine the impact of hen housing systems on prevalence, diversity, and antimicrobial resistance of Salmonella, Campylobacter, Listeria, and Enterobacteriaceae associated with the production environment and eggs.
The housing of laying hens has become a matter of state and federal regulatory concern, as well as a purchasing consideration for consumers. While the shift in European Union laying hen housing requirements resulted in a plethora of research, most have limited similarity to the management systems utilized in the U.S. This project will, through national collaborative efforts, examine the impact of U.S. commercial hen housing systems on hen health and well-being, egg and environmental microbiology, and Salmonella infection and transmission. The collaborations associated with this project allow for a comprehensive examination of hen housing systems in a cost-effective manner. Furthermore, the project incorporates the research gaps identified by federal and state regulatory groups, as well as large and small egg producers. The research project will determine the impact of hen housing systems and laying hen genetic strain on the prevalence of Salmonella, as well as other human pathogens. Additionally, this project will determine the infection rate and transmission of various Salmonella strains within these housing systems. The effects of housing and management strategies on egg quality will also be assessed. The data generated from the project can be utilized by large and small egg producers to develop informed production management plans and state and federal regulatory groups to determine regulatory needs to ensure safe, high quality eggs reach consumers.
This report is for a new project which continues the research from expired project 6040-32420-002-000D, "Evaluation of Management of Laying Hens and Housing Systems to Control Salmonella and Other Pathogenic Infections, Egg Contamination, and Product Quality/" Refer to project 6040-32420-002-000D for more information about research progress and accomplishments in FY 2021. Egg handling and ambient temperature impacts on physical and microbial quality during extended storage. The impact of handling practices in the shell egg processing facility and post-processing ambient storage temperature on physical and microbial quality of eggs during 6 months of storage is being assessed. The study is necessary for USDA AMS to set shell egg import and export certification standards. Validation of USDA AMS sampling rates in official shell egg processing facilities. A study is underway, in conjunction with Purdue University, to determine if current AMS sampling rates (1 in every 100 cases) are effective and efficient at maintaining shell egg grading standards. Development of instrument enhanced grading parameters for shell eggs in official USDA AMS shell egg processing facilities. The validation stage of a long-term study, in conjunction with AMS and Purdue University, is currently underway to determine machine settings for large capacity shell egg processing equipment that will ensure packaged product meets shell egg grade standards. Development of training materials for shell egg processing facility pre-operational sanitation assessment. In collaboration with USDA AMS and Purdue University, video footage collected during FY 19 is being utilized to develop online training content for both AMS shell egg graders and egg processors. Twelve training videos are now available (free) with over 5,800 views. The project is ongoing.