The objective of the Feed-a-Gene project (2015-2020; H2020 grant agreement 633531) was to adapt the feed, the animal, and the feeding techniques to improve the efficiency and sustainability of monogastric livestock production systems. For ‘feed’, we concluded that non-GMO European soybeans can be processed in small-scale processing plants to obtain soybean meals with similar or even better nutritional quality as imported soybean meals. Also, there is a potential for the use of green biomass to extract protein for monogastric animals to replace imported soybean meal in organic farming. Concerning the ‘animal’, monogastric animals have to rely more on alternative feed resources that are less or not in competition with other uses. These resources are typically more variable and of poorer nutritional quality. With new molecular and automated records, animals can be selected that do best with feed that is worse and transform these alternative feeds into meat, respecting their welfare and robustness and limiting environmental impacts. Precision livestock feeding is a novel technology that can be using to provide tailored diets to animals according to their (individual) requirements, thereby reducing nutrient excretion and the environmental impact of livestock production. The potential of precision livestock farming is much larger than what we explored in Feed-a-Gene (e.g. precision medication, design of housing systems). It is not a question of ‘if’ but of ‘when’ these systems will be implemented, and ‘how’ society will perceive trade-offs of improved resource use, reduced environmental impact, improved welfare versus a perceived further industrialization of livestock production.