Grain particle size is one of the primary factors that dictate starch digestibility in both ruminant and mono-gastric animals. Grain that is not processed well enough results in slow or incomplete digestion and low feed efficiency. Grain particle size can be measured accurately and precisely by utilizing the method descrived in ASAE S319.4, which includes Ro-Tap shaking through a set of 14 sieves with various sized apetures.
|U.S. Sieve #||Micron Opening|
A Grain Particle Size report will include the weight and percentage of the same retained on each sieve as well as calculations of the Mean Particle Size (MPS) and 1 Standard Deviation Distribution. Typical MPS values found for various processing methods are as follows:
|Fine Ground - Dry Corn||<750|
|Medium Grind - Cry Corn||750-1000|
|Coarse Ground - Dry Corn||>1000|
|Whole - Dry Corn||>4000|
|Fine Ground - High Moisture Corn||<1000|
|Coarse Grind - High Moisture Corn||1000-2500|
|Rolled - High Moisture Corn||1000-2500|
|Coarse Rolled - High Moisture Corn||>2500|
|Whole - High Moisture Corn||>4000|
Prolamin content and extent of fermentation can also have a significant effect on the digestion of starch in ruminants. UW Grain 2.0 incorporates grain particle size, prolamin, and the extent of fermentation to give an accurate estimate of digestibility.