A shredding machine (2) for bales (4, 4', 4'', 4''') of straw or hay having a length (W2), said shredding machine (2) comprising a shredding section (46) comprising one or more rotatably arranged rotary rakes (10, 10') and a conveyor (20) configured to convoy bales (4, 4', 4'', 4''') along the longitudinal axis (Y) of the conveyor (20) towards the shredding section (46). The length (W3) of the rotary rakes (10, 10') is larger than the length (W2) of the bales (4, 4', 4'', 4'''). The shredding machine (2) according to the invention, is capable of delivering loosened straw or hay in a manner in which the heating value varies less than the prior art shredding machine as function of time.
