A Method for Determining and Expressing the Size of Feed Particles by Sieving

Abstract

THERE has long been a need for a method of measuring and expressing the size of feed particles. General terms such as “coarse”, “medium” or “fine” are ill-defined at best and subject to variation in usage. References to hammermill screen size are relatively descriptive, but the resulting particle size varies widely because of factors such as hammer speed, extent of wear on hammer and screen, screen area, air flow, method of discharge, kind of grain, moisture content of grain and other variables (Baker and Farrell, 1961; Stevens and Pfost, 1962).A direct measure of the feed particles is obviously more practical than attempting to stabilize the factors that influence the fineness of grind. Two previous measures of feed particle size have been adopted by the American Society of Agricultural Engineers (1961) and the American Society of Animal Science. The method given in this paper is a refinement of the previous…