ABSTRACT
In most countries, grain which is destined either for human consumption or for use as animal feed is cleaned by removal of straw, soil and foreign seeds. This is achieved by the use of seed cleaners. They consist of a series of blowers and sloping, shaking screens, which separate particles on the basis of density and size. The contaminants, collectively known as screenings, are generally defined on the basis of the allowable content of broken grain, fiber, weed seeds (some specifically mentioned) and dust. Definitions for the United States and Canada are presented in an Appendix on page 404 (Canada Grains Act, 1984; Assoc. Am. Feed Control Officials, 1989). Although screenings are most commonly used as an ingredient in diets fed to ruminants, they may also find use in swine production.
