A method for manufacturing feed pellets, and a plant for the implementation of this method have been explained. The aim has been to improve the manufacturing of porous pellets, first and foremost to achieve a better control of the porosity of the pellets than the known techniques. The pellets come from a pelletizing machine (1) into a pellet chamber (3) which is kept at a pressure lower than the ambient pressure. From the chamber (3) the pellets are passed through an outlet (5) having a gate lock body (6).