LAUSR

As baseline environmental footprints of beef cattle production are established, mitigation strategies through cow-calf dietary and production management can be evaluated. Our objective was to quantify environmental benefits obtained by beef cattle production through implementation of cow-calf management strategies. Ten cow-calf management strategies were identified related to animal performance, feed management, or pasture management. Each strategy was incorporated into 20 representative beef cattle production systems and simulated with the Integrated Farm System Model (IFSM) using local soil and climate data. A combined strategy was identified based upon the results of individual strategies, which was also simulated with IFSM. Farm-gate life cycle assessment was used to estimate carbon (C) footprint, fossil energy use, blue water use, and total reactive nitrogen (N) loss for all production systems and strategy combinations. Averages of each environmental metric for the cow-calf sector were based on weighted averages of regional cow inventory data. National estimates of environmental impacts were based upon number of cattle represented by each production system. Feed efficiency, terminal cross sires, and reduced cow body size strategies had greatest effect on C footprint (reductions of 1.31, 1.15, and 0.71 kg CO2e/kg CW, respectively from a baseline of 16.34 kg CO2e/kg CW). Calving season, reduced cow body size, and improved fiber digestion increased fossil energy use (7.8%), while improved feed efficiency and calf implant use reduced fossil energy use (7.4%). Blue water use was reduced by a greater extent from improved feed efficiency (4.6%) and reduced cow body size (5.3%) compared to other strategies (0.6%). Total reactive N loss was reduced by 7.0 and 6.9% through improved feed efficiency and reduced cow body size, respectively. Combining strategies reduced C footprint (18.2%), fossil energy use (18.6%), blue water use (18.9%), and reactive N loss (16.2%).