Jan 01, 2005 · For poultry feed, 55 m/s is the most frequently used speed. Grinders with variable speed allow adapting speed to the raw materials and to the fish feed machines for feed particle size. Grinder grills: the two important criteria are mesh diameter (from 2 to 10 mm), and the percentLIMAe of holes in the grill (from 27 to 52 %).