Studies on the alimentary tract of merino sheep in South Africa. X. Notes on the digestion of some sugars in the rumen of sheep

Abstract

1. Studies were undertaken on the disintegration of various carbohydrates (sugars and cellulose) in the rumen of sheep. For this purpose were utilised adult merino sheep with permanent fistulae in the rumen. 2. With the animals on standardized diets, ruminal ingesta was periodically withdrawn by aspiration through the fistula. This material was then filtered through fine muslin and fermentative activity of the filtrate determined by measuring the volumes of gas evolved in fermentation tubes following the addition of different concentrations of sugars. 3. Results obtained show the extreme rapidity with which sugar is fermented by rumen ingesta, the rate and degree of fermentation depending on (a) type of sugar used, (b) its concentration in the tubes, and (c) the nature of the ingesta and the time of its withdrawal. 4. Accompanying the evolution of gas, there is a rapid rise in total acids within the tubes. This, however, cannot be wholly accounted for either as volatile acids or as ether soluble non-volatile acids, thus necessitating further investigation. 5. Methods are described for determining the rate of disappearance of cellulose within the rumen, through the enclosure of weighed amounts of cellulose in thin silk bags and the suspension of these through the rumen fistula. Further work along these lines is still in progress.