The invention relates to a covering system for silage preparation. The covering system (1) comprises at least one underlay film (2), which rests on the surface of a feedstuff (6). The underlay film (2) has an oxygen barrier layer (3). At least 50 wt% of the oxygen barrier layer (3) consists of one or more material/s from the group comprising polyamide, co-polyamide, polyester, co-polyester, polyethylene, ethylene vinyl alcohol, polyvinyl alcohol, or mixtures thereof. According to the invention, the underlay film (2) has an inner protective layer (4) facing the silage.