Objective 1) Develop alternative strategies to replace or reduce the use of conventional antibiotics for improved growth, animal health and product safety. A. Develop alternative antimicrobials to treat or prevent diseases in swine and dairy. B. Develop transgene-expressing cell transplantation methods to enhance growth rate and to treat or prevent diseases in swine. C. Develop effective dietary/nutritional regimens that can be implemented to maintain the healthful character of the gut of weanling swine. Objective 2) In order to develop alternatives to antibiotic growth promoters, identify mechanisms underlying the growth promoting effects of antibiotics in swine. A. Establish which microbial population distribution patterns are predictive of GI health and efficient nutrient utilization. B. Identify biomarkers of gut health and efficient nutrient utilization that are associated with specific changes in the metabolomic profile of the weanling pig gut. Objective 3) Develop and/or utilize molecular tools to understand the role of genes relevant to health, growth or intestinal function in swine and dairy with the goal of identifying targets for alternatives to antibiotic growth promotants. A. Establish in vitro approaches (intestinal pig cell lines) to model the role of specific metabolites or cytokines in gut nutrient absorption and gut immunological responses. B. Develop and apply site-specific gene modifying technologies to modify intestinal epithelial cell function and metabolism. C. Target specific bovine genes for editing that are relevant to health, milk production and milk quality.