A covered hopper car load. Silage are forage plants such as corn, legumes, and grasses that have been harvested at early maturity, finely chopped, packed tightly to exclude air, and stored in tower silos, pits, or trenches. Silage also is a by-product of the non edible waste in the processing of grains, citrus foods, fruits & vegetables. SIlage can be used as is or mixed with other animal feeds & nutrients.