Feed ingredients Maize (Corn)
Maize (Corn)
Description
Maize is a major staple food grain throughout the world, particularly in Africa, Latin America and Asia, and a major feedstuff in developed countries. The maize grain has many food (grain, flour, syrup, oil…) and non-food usages (cosmetics, adhesives, paints, varnishes). Maize starch and oil are also major products. The maize grain is a major feed grain and a standard component of livestock diets where it is used as a source of energy. Other grains are typically compared to maize when their nutritional value is estimated. Many by-products of maize processing for flour (hominy feed, bran, germs, oil meal), starch (corn gluten feed, corn gluten meal) and alcohol/biofuel industries (distillers’ dried grains and solubles) can be fed to animals.
Corn contains approximately 70 percent starch on a dry-matter basis. Other important fractions in the corn kernel include protein, fiber and minerals.
Maize breeders have created many cultivars that correspond to specific climatic or agronomic conditions and uses. "Dent corn" maize is the most widely grown type of maize and the one typically used for feed. Other types (flint corn, popcorn, sweet corn, flour corn) are more intended for food uses. Some varieties have been created to improve the industrial or nutritional value: high lysine, high tryptophan, high oil, high amylose, low phytate, etc. Brown midrib maize has a lower lignin content resulting in an increased digestibility in livestock. Genetically-modified (GM) maize varieties have been designed to improve grain performances (herbicide resistance, pest resistance, higher yields).
Processes
Maize grain is fed as dry maize grain (less than 15% moisture) or high-moisture maize grain (22 to 28% moisture). When maize is dried, it should not be heated over 150°C, since this reduces nutritive value and acceptability to pigs (Patience et al., 1995).
Dry or high-moisture maize grain can be available as:
unprocessed = whole grain, shelled
finely ground = fine meal
cracked = medium particle size
steam-rolled = moistened and flattened grains
steam-flaked = heated, moistened and pressured grains (flakes)
Each form has its advantages and disadvantages when feeding livestock
**For optimum dietary utilization, corn should be processed by rolling, cracking or coarsely grinding prior to feeding. The decision to process corn should be based on efficiencies gained from processing compared with the cost of processing.**
