Polydimethylsiloxane and/or siloxane (silicone)-derived chemical compounds are used to coating harvested forages to protect against rain and/or other weather damage and to suppress mold and spoilage in harvested forages. The PDMS compound and derivatives thereof are also found to suppress the damage resulting from oxidation within the feedstuff mass. When applied, PDMS coats the feedstuff and is included in the moisture portion of the feed or forage mass. This helps preserve the feed quality and slows the damaging effects of spoilage organisms and oxidation.