Abstract
Using the continuous infusion isotope dilution technique, the glucose utilization rate has been compared in three groups of sheep on different diets. Glucose was utilized at the mean rate of 1·8 mg./kg./min. on a daily ration containing 126 g. crude protein, at the mean rate of 2·8 mg./kg./min. on a daily ration containing 197 g. crude protein, and at the mean rate of 4·3 mg./kg./min. on a daily ration containing 460 g. crude protein. The mean percentage of expired carbon dioxide that was derived from glucose was 3·5, 6·5 and 8·9 respectively on the three diets.