520 Late-Breaking: Effect of Technology on Environmental Emissions from Four Representative U.S. Feedlots and the Beef Production System

Abstract Our objective was to evaluate effects of technological management strategies on environmental impacts and net returns feedlot operations in the United States. Feedlot were simulated with Integrated Farm System Model (IFSM 4.6; USDA-ARS, University Park, PA) quantify baseline production full US beef cattle systems. Strategies included: ionophore, implant, ractopamine hydrochloride, combined (ionophore, hydrochloride; I+I+R), lubabegron, reduced mortality rate, improved fiber digestion. Days feed adjusted whenever necessary according practices typical commercial feedlots. Subsequently, annual number finished by operation days maintain consistent one-time capacities. Mitigation individually modeled IFSM for each calculate intensities (expressed per kg gain) greenhouse gas (GHG) emissions, fossil energy use, blue water consumption, reactive nitrogen loss. Additionally, estimated operation. Feedlots then integrated simulations cow-calf, stocker, backgrounding estimate carcass weight) system. Carbon emission intensity most using I+I+R strategy (10%), followed implant (6%) ionophore (5%) alone. Similarly, use greatest (9%), (5%), implants (4%). Reductions also (9%). Net increased all compared return improvements observed ($114/finished animal) ($66/animal). Consistent results across four when quantified Implementing (7%), hydrochloride (4%), lubabegron (4%) feedlots resulted reductions emissions.