Equinews.com - Full Article
By Kentucky Equine Research Staff · May 21, 2012
The grains in most of today’s feeds are processed in some manner before being fed. Although some grains can be fed whole, processing, even if it is only grinding, usually makes the nutrients more available to the animal, thus improving digestibility and feed efficiency.
Grinding is done using either a hammermill or roller mill. Hammermills grind primarily by the impact of free-swinging hammers on the grain as it falls through the grinding chamber. Screens with specifically sized holes surround the grinding chamber and as the grain particles become small enough, they pass out through the holes. Roller mills have pairs of rolls, often two or three pairs per mill, that crush the grain as it passes between the rolls. The space between rolls can be adjusted to give various particle sizes.
Popping is achieved by rapid, intense heating of grain. Rapid heating with 700 to 800° F (371 to 427° C) hot air makes the moisture in the kernel turn to steam, thereby expanding the grain. Most feed grain does not pop like popcorn, but grain does expand and starch is gelatinized, resulting in the grain being much more available to digestive enzymes or organisms. Because popped grain has a larger volume per weight, it also contains a lower level of nutrients than the same volume of unpopped grain and sometimes an animal cannot consume sufficient feed, resulting in reduced gains. Many users roll the popped grain to increase the bulk density and to help flatten the grain for easier handling...
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