Studies on the alimentary tract of Merino sheep in South Africa. XV. The influence of different factors on the rate of cellulose digestion in the rumen and in ruminal ingesta as studied in vitro

Abstract

(1) The rate of cellulose digestion in ruminal ingesta was studied both in vivo and in vitro by a new technique in which cotton threads were used as test material. (2) It was found that the rate of cellulose digestion was markedly influenced by the diet. (3) The appetite for either lucerne or grass hay was directly affected by the rate of cellulose digestion. (4) On a basic diet of poor quality grass hay both cellulose digestion and appetite were stimulated by small amounts of sugar but markedly depressed by excessive amounts. More sugar could be tolerated if protein was also given. Optimal cellulose digestion necessitated a balance between readily available carbohydrate and protein. (5) Excess protein suddenly introduced after a period on a diet low in both protein and carbohydrate caused marked inhibition of cellulose digestion and inappetence. One case of sudden death was possibly associated with ammonia poisoning.