Ease of Hydrolysis of the Hemicelluloses of Forage Plants in Relation to Digestibility

Abstract

Forage grasses were treated with dilute sulfuric acid and simple carbohydrates derived from the hemicelluloses were determined quantitatively. The acid treatment caused both solubilization and hydrolysis of the hemicelluloses, depending on the severity and duration of the treatment and on the degree of lignification of the forage. The ease of solubilization and/or hydrolysis was measured by comparing the quantity of carbohydrates found in the extracts under standard conditions of partial hydrolysis with the total in the intact forage. The ease of solubilization and/or hydrolysis of the hemicelluloses was positively correlated with the digestion coefficient of dry matter in a number of forages including grasses and legumes. The pattern of hemicellulose breakdown by acid hydrolysis was similar to that by in vitro digestion.