Many livestock and aquaculture feeds compete for resources with food production. Increasing the use of food system by-products and residues as feed could reduce this competition. We gathered data on global food system material flows for crop, livestock and aquaculture production, focusing on feed use and the availability of by-products and residues. We then analysed the potential of replacing food-competing feedstuff—here cereals, whole fish, vegetable oils and pulses that account for 15% of total feed use—with food system by-products and residues. Considering the nutritional requirements of food-producing animals, including farmed aquatic species, this replacement could increase the current global food supply by up to 13% (10–16%) in terms of kcal and 15% (12–19%) in terms of protein content. Increasing the use of food system by-products as feed has considerable potential, particularly when combined with other measures, in the much-needed transition towards circular food systems.

许多牲畜和水产养殖饲料与粮食生产争夺资源。增加使用食品系统副产品和残留物作为饲料可以减少这种竞争。我们收集了有关作物、牲畜和水产养殖生产的全球粮食系统物质流动的数据，重点关注饲料使用以及副产品和残留物的可用性。然后，我们分析了用食品系统副产品和残留物替代与食品竞争的饲料（这里是占饲料总用量 15% 的谷物、全鱼、植物油和豆类）的潜力。考虑到食用动物（包括养殖水生物种）的营养需求，这种替代可以将当前全球食物供应量增加 13%（10-16%）（以千卡计）和 15%（12-19%）（以千卡计）的蛋白质含量。