Fig. 5From: Hotspots and bottlenecks for the enhancement of the environmental sustainability of pig systems, with emphasis on European pig systemsPrinciples of circularity and flows in the context of circular agriculture. Food waste from human consumption or industry by-productions are used as feed inputs in livestock production. Examples of waste and by-products are food waste, former foods, non-edible plant residues from crop production, by-products from biorefinery, or animal by-productsBack to article page