The ERA-NET project SuSI deals with immunocastration (IC) as a sustainable alternative to pork production with surgical castrates and boars with the aim to optimize pork production on a social, environmental and economic level. Most male piglets in the EU are surgically castrated, which is painful and violates their physical integrity. Raising entire males is not the hoped-for alternative, mainly due to boar taint, while the use of anaesthesia/analgesia during castration also encounters challenges at the level of animal welfare, environment and user safety. The key findings of SuSI are: (1) IC works reliably under different housing conditions and reduces behavioural as well as animal welfare problems; (2) IC effectively reduces boar taint, with differences between animal trials. The chance of boar taint was not completely absent in all trials; (3) IC produces meat of high quality comparable to surgical castrates and is thus an alternative for high-quality traditional products and outdoor systems; (4) IC is ecologically efficient, when feed is adapted to dynamic requirements; (5) IC has a high level of consumer acceptance as an ethical concept as well as due to the good sensorial quality; (6) IC has economic and productivity benefits – if it gains market acceptance. Stakeholders at EU level are generally ready to abandon castration without anaesthesia/analgesia, while the preference for alternatives depends on external factors, e.g. the production system and the market. SuSI offers optimized knowledge of IC to support the stakeholders in their decision-making processes for consumer-acceptable pork production across the EU. IC can make the EU pig industry more sustainable and for some countries more competitive.