To identify proper strategies for future feed efficient pig farming animal selection scenariosshould be evaluated. Selection based on residual feed intake (RFI) has been proposed toimprove feed efficiency. The aim of this project is to develop a model to account for individualanimal performance in life cycle assessment methods to quantify the economic andenvironmental impacts of the selection. Experimental data from 118 pigs were collected fromlines divergently selected for residual feed intake (low line, more efficient pigs, LRFI; highline, less efficient pigs HRFI). A parametric model was developed for life cycle assessment(LCA) based on the net energy fluxes in a pig system. A nutritional pig growth tool, InraPorc®,was included as a module in the model to embed flexibility for changes in feed, traits andhousing conditions, and to simulate individual pig performance. The comparative LCA showedthat LRFI pigs had lower environmental impacts than HRFI pigs, on climate change,acidification potential, fresh water eutrophication potential and land occupation. A sensitivityanalysis based on pig performance traits revealed that these environmental impacts were leastsensitive to carcass lipid contents and back fat thickness, and most sensitive to protein content,growth rate, feed intake and feed conversion ratio. Further modelling showed line differencesin requirements for energy, protein and amino acids, which was used to formulate separatediets adjusted to the line requirements. The environmental assessment of the simulated lineresponses to these diets revealed that tailored diet formulation, according to the innaterequirements of the pigs, is a promising strategy for achieving more sustainable pig production.An additional economic optimisation is currently being developed to propose an integratedframework to pig production stakeholders