The long-term goal is to understand how management practices and challenges influence Salmonella spp. shedding from laying hens in cage-free systems. The specific objectives for this grant is to: A. Examine the role of northern fowl mites (NFM) on laying hen performance and welfare. B. Assess impacts on the shedding of Salmonella spp., as well as environmental and egg microbiology. C. Evaluate egg quality as impacted by NFM.