The fermentation characteristics of diets containing acid-treated beech-sawdust in an artificial rumen

Abstract Two experiments were conducted to examine the feasibility of substituting hay with chemically treated beech-sawdust in diets of ruminants. Experiment I was aimed at comparing alkali treatment with acid treatment under pressure as a method of improving the nutritive value of sawdust. Experiment 2 examined the effects of incorporating acid-treated beech-sawdust as a substitute for hay, with or without wheat bran, on fermentation characteristics using an artificial rumen (Rusitec). Untreated sawdust had a very low DM digestibility (5%). Treatment with a 4% solution of sodium hydroxide increased the digestibility to 17% which was still too low to be of any practical significance. In the presence of bran (20%), acid treatment increased DM digestibility of a beech-sawdust diet to 48%, 10% units lower than that of the control diet of hay. Examination of the effects of various dietary combinations of acid-treated beech-sawdust, hay and wheat bran on rumen fermentation characteristics showed that acid-treated sawdust could be a suitable substitute for hay (up to 70%) in diets of ruminants provided adequate amounts of energy and nitrogen were made available for optimizing rumen fermentation.