August 26, 2013
Penn State Particle Separator
2-Sieve Model (19 mm and 8 mm)
fi rst available in 1996
Note: Th
e recommendations for the percent remaining on the upper sieve vary depending on the conditions
described in this table. Graphs on the following pages show boxes that indicate both recommendations. Users
should consider their conditions and compare their results to the most appropriate “target” range.
Recommended distribution of particle size (percent remaining on each screen) for
corn silage, haylage, and TMR samples
Screen
Pore Size
(inches)
Particle Size
(inches)
Corn Silage
Haylage
TMR
Upper Sieve
(19 mm)
0.75
> 0.75
2 to 4% if not
sole forage
10 to 15% if chopped
and rolled
10 to 20% in
sealed silo
15 to 25% in bunker
silo, wetter
6 to 10% or more
3 to 6%, focus on
total NDF and
forage NDF
Middle Sieve
(8 mm)
0.31
0.31 to 0.75
40 to 50%
30 to 40%
30 to 50%
Bottom Pan
< 0.31
40 to 50%
40 to 50%
30 to 40%
