Objective 1. Determine the genotypic and/or phenotypic factors associated with the levels and persistence of pathogens and antibiotic resistance in the host animal and the livestock production environment. Sub-objective 1.1 - Determine genotypic or phenotypic factors associated with persistence of E. coli O157:H7 in cattle production. Sub-objective 1.2 - Determine animal host genotypes that confer resistance/susceptibility to pathogen infection. Sub-objective 1.3 - Evaluate the influence of spatiotemporal, environmental, and wildlife factors on pathogen and antibiotic resistance occurrence and transmission dynamics in cattle and waterways in a pasture-based production system. Objective 2. Develop and evaluate intervention strategies that reduce or eliminate the occurrence, transmission or persistence of foodborne pathogens in host animals, including cattle and swine, and the environment. Sub-objective 2.1 - Develop a high-throughput procedure to identify and measure antibiotic resistance genes. Sub-objective 2.2 - Identify alternatives to antibiotics for use as growth promoters in production animals. Sub-objective 2.3 - Determine the effect of calcium hydroxide application to feedlot pens on E. coli O157:H7, total E. coli, and antibiotic resistance on feedlot pen surfaces and in cattle.