Silo

Silo, structure used on farms to preserve grasses, or silage, for livestock feed. Most silos are cylindrical and up to 50 ft (15 m) high. They are made of an air-tight material, such as glass or porcelain on the inside, and a sturdy material such as metal, brick, tile, concrete, or wood on the outside. The sweetness of certain grasses or the addition of a solution (such as sulfur dioxide) promotes fermentation, a natural process that prevents spoilage. Steady deposit and removal of silage keeps the grasses in the silo fresh for year-round feeding of livestock.