Objective 1: Determine the impact of meat animal dietary changes on manure and the environment. Sub-objective 1A: Determine if a moderate and aggressive implant strategy with and without ß-agonists reduces odorous volatile organic compounds (VOCs) and GHG production from fresh and stored beef manure (Spiehs). • Sub-objective 1B: Determine if the addition of ferric citrate to beef feedlot diets reduces nutrient excretion, GHG, and odorous VOCs from fresh and stored beef manure (Spiehs). • Sub-objective 1C: Determine if the addition of an ionophore to improve feed efficiency reduces odorous VOCs and GHG production from fresh and stored beef manure (Spiehs). Objective 2: Develop practices for reducing environmental impacts of nutrients, pharmaceutical residues, gaseous emissions and other agricultural waste on soil and air quality through improved manure management and control systems. • Sub-objective 2A: Conduct a series of laboratory studies to determine the impact of within pen spatial location and climatic conditions on GHG and odorous VOCs emissions from beef feedlot pen surfaces and the effectiveness of surface amendments as a mitigant (Woodbury and Spiehs). • Sub-objective 2B: Evaluate the use of electromagnetic induction (EMI) and response surface sampling design (RSSD) as tools for predicting emission spatial variability on commercial-sized pen surfaces (Woodbury). • Sub-objective 2C: Evaluate the addition of surface amendment on commercial-sized pens for reducing odorous VOCs and GHG emissions (Woodbury and Spiehs). • Sub-objective 2D: Determine occurrence of antimicrobial resistance following land application of cattle manure to agricultural soils (Spiehs and Woodbury). • Sub-objective 2E: Determine residual steroid and ß-agonist concentrations in feces and urine of beef cattle administered a moderate and aggressive implant strategy with and without ß-agonists (Spiehs). Objective 3: Develop measurement technologies for manure contaminants that can be used for conducting field-scale fate and transport studies in crop and pasture systems. Sub-objective 3A: Develop techniques and analysis software protocols that will enable the wide-spread use of resistivity array (RA) technology by pond managers as an early-warning system for detecting unintended sub-surface discharge (Woodbury and Eigenberg). • Sub-objective 3B: Develop techniques for tracking and mapping the 2-dimentional transport of antimicrobial residues in crop and hay fields (Woodbury and Eigenberg). • Sub-objective 3C: Determine the effectiveness of flocculation for removing excreted veterinarian pharmaceuticals from beef runoff wastewater and swine-manure lagoon water (Woodbury and Spiehs).