Life cycle analyses of eight pork production strategies for three environmental impact categories yielded a range of results, from a 17 percent increase in global warming potential (removing preventative antimicrobials) to approximately 3 percent reduction in energy use (immuno-castration). Based on the LCA results, the following pork production strategies increased environmental impact metrics across all three impact categories: Anesthesia, not using antimicrobials for growth promotion or disease prevention. Conversely, using immuno-castration, entire male production and pen gestation production strategies decreased global warming potential and energy use, and immuno-castration reduced water use. These results are the product of simulation of pork production strategies combined with unit process LCAs; these models are very sensitive to time in the barn at each growth stage, rates of conversion of feed to lean meat, and mortality rates. Model sensitivity and uncertainty are difficult to characterize due to the limited observational data for which the pork production models were calibrated, and the limited Life Cycle Inventory data for alternative production strategies.