agriculture has a special and important place in society because it ensure the production of food and fibre is essential to food security and to social and economic development employment maintenance of the countryside and conservation of land and natural resources and helps sustain rural life and land
If we use farm animals for what they are good at - converting by-products from the food system and grass resources into valuable food and manure - they can contribute significantly to human food supply, while at the same time reducing the environmental impact of the entire food system. By converting these so-called low-opportunity-cost feeds, farm animals recycle biomass and nutrients into the food system that would otherwise be lost to food production. Rearing animals under this circular paradigm, however, requires a transition from our current linear food system towards a circular one. Here we present a biophysical concept for the role of farm animals in a circular food system, essential for meeting dietary recommendations within the boundaries of our planet.