Livestock are an indispensable element of the agricultural bioeconomy, transforming non-edible biomass into high-quality food and returning a large proportion of the plant nutrients contained therein to the agricultural material cycle via farmyard manure. This non-edible biomass makes up the majority of the total agricultural biomass and comes from grassland, co-products of food-producing plants (e.g. straw), intercrops in the course of crop rotation and from by-products of the industrial processing of plant sales products. However, potentially edible biomass also finds its way into livestock feed. Especially in the case of poultry, it enables a high efficiency of transformation of biomass into high-quality food protein and is coupled with a lower consumption of resources (land, water) and less environmentally relevant emissions than in the case of ruminants (e.g. cattle, sheep). However, due to the increasing scarcity of agricultural land, this form of food competition between humans and livestock will have to decline in the future, while ruminants, thanks to their ability to utilize non-edible biomass, will gain in importance despite higher environmentally relevant emissions. Provided that only the non-edible biomass that is available anyway is fed, this does not have a detrimental effect on the consumption of land, water and other resources. In order to minimize the disadvantages in terms of transformation efficiency and emissions, more attention must be paid in particular to the feed value of the non-edible agrarian biomass. Measures range from the supplementation of limiting nutrients (e.g. amino acids) and the elimination of anti-nutritive ingredients to the improvement of the digestibility of the non-edible components of crops through breeding or genetic engineering.