The Penn State particle separator, commonly called “the shaker box,” is a very useful tool for conducting nutritional analysis on dairy farms. The particle separator is a “square box” made up of two or three sieves having different sized holes at each level superimposed on a bottom pan.


Feed particles retained on each level are then weighed. The proportion of feed particles retained on the top two sieves is considered a good estimate of the proportion of physically effective particles that are long enough to cause rumination in the cow.
Source: January 2009 issue of MilkPRODUCER magazine published monthly by Dairy Farmers of Ontario. Page 30