Effect of Heating Starch on its Digestion by Rumen Microorganisms

Abstract

To determine whether the heating of starchy feeds increases the rate of starch dissimilation by rumen microorganisms, corn starch, ground corn, and a commercially heated corn were exposed to various heat treatments then incubated with rumen microorganisms. The disappearance of readily hydrolyzable dry matter was determined. Results were in keeping with the concept that the application of moist heat to starch or starchy feeds brings about hydration of the starch, and that hydrated starch is digested more rapidly by rumen microorganisms than untreated starch. Autoclaving ground corn or a commercially heated corn without the addition of water resulted in a decrease in the rate of digestion of the readily hydrolyzable dry matter.