Sustainable pig production is characterized by economic profitability through improved productive output, while maintaining animal health and welfare, and without compromising environmental resources. This study aims to enhance sustainability of European pig production through improved feed efficiency (FE) at different scales. The supporting objectives are to 1) Evaluate the consequence of improved FE for fitness, to improve animal robustness; 2) Evaluate if improved FE can be sustained with more reliance on local feed resources and feedstuff co-products; 3) Evaluate the environmental, social and economic impact of improved FE on local feed resources and feedstuff co-products; and 4) To develop future sustainable pig production systems. We approach this by: 1) Evaluation of robustness traits in experimental and commercial pigs; 2) Evaluation of FE and robustness in response to feedstuff co-products and local pig diets; 3) Assessment of the environmental and social impact of pig production as enhanced by transforming low quality feed, through Life Cycle Assessment (LCA) analysis; and 4) Modelling of future sustainable production systems. This project combines the expertise of European research groups in cooperation with those from the USA and Australia through a multidisciplinary approach. The work is relevant to Research Area 1: FE affects profitability of animal production through reduced feed costs, but economic benefits are also directly influenced by animal robustness. Efficient use of local resources may improve the productivity, resilience and competitiveness of European pig production; Research Area 2: Improving FE of pigs in transforming low quality feed may improve local resource use and enhance the environmental sustainability of European pig production; Research Area 3: Understanding the implications of improving FE on animal robustness may improve animal welfare, breeding strategies and consumer acceptance of pig production and breeding practices.