A farm outbuilding is a structure that is built on a farm to provide additional storage or shelter for animals and equipment. The most common farm outbuildings are barns, sties, and silos. A BARN is a large building used for storing hay, grain, and other agricultural products. A STY is a small enclosure for pigs, usually made of wood or stone. A SILO is a tall cylindrical structure used for storing grain or other materials.