Front attachment device (30) for screening a pit opening of a silage silo, comprising:- a frame (31)；- a roof (32) which is connected to the frame and extends substantially horizontally and which is configured to screen at least a part of a first side of the pit opening in the silage silo；- screening means (76) connected to the frame and adapted to screen at least a part of a second side of the pit opening； and- displacing means (38) arranged on the frame；wherein the roof and the screening means are together configured in a first mode to screen the pit opening of the silage silo.
