Submitted to: Encyclopedia of Agricultural, Food, and Biological Engineering
Publication Type: Book / Chapter
Publication Acceptance Date: December 15, 2009
Publication Date: N/A
Technical Abstract: Forages are a major component of the diet for cattle and other livestock. In most parts of the world, forage production is seasonal so that some forage must be harvested by the farmer and stored. The two main systems for storing forage are as hay and silage. With hay, the forage is dried to approximately 15% moisture, wet basis, and then most often packaged into rectangular or round bales. The bales may be stored indoors or outdoors with or without cover. The predominant method for storing hay within a region is dictated usually by climate and its effect on storage losses. With silage, the forage is stored at higher moisture, typically 40 to 85%. The crop may be placed in a structure (silo), pile or bale, but the key to preservation is that the crop is sealed to remove oxygen and allow lactic acid bacteria to ferment crop sugars to lactic acid and other products that lower crop pH. The combination of the absence of oxygen, fermentation products and low pH preserve the forage.