Animal by-products (ABPs) are material of animal origin not intended for human consumption. If they are not properly and safely used or disposed of, they represent hazardous waste. In order to eliminate risks, all ABPs must be processed to make them harmless to the environment, animals and humans. The processing of ABPs also contributes to sustainable development thus making the circular economy function. Namely, processed ABPs can be re-used under certain conditions in the compound feedingstuff, fuel and fertiliser industry.