The decarbonisation of industrial and agricultural production, including livestock farming, has become a global trend, and many countries are aiming for carbon neutrality by 2050. Consequently, future efforts in feed preparation, processing and livestock production will prioritise carbon-neutral research and development. This chapter introduces the field of feed production and livestock rearing, emphasising the use of agricultural by-products to create feed. The goal is to enhance livestock-rearing technology and contribute to a green, decarbonised society. This approach not only promotes harmony with nature but also fosters sustainable practices that allow for resource cycling and synergy between farming and livestock operations.