A life cycle assessment approach is proposed to quantify four environmental impacts at the individual pig level. The approach was applied to two lines divergently selected for feed efficiency, including simulations of performances with two diets. Significant line differences were obtained with least-cost diets for environmental impacts and profit (P < 0.001), with a general advantage of the more efficient line. The optimised diets reduced the disadvantages of the less efficient line. Correlations between profit and environmental impact were high for feed efficiency (> 0.85), and moderate (< 0.45) for growth rate and body composition. Applied to pedigreed populations, this framework will provide genetic parameters of environmental impacts to improve the sustainability of livestock production.