Effects of Dietary Energy Density and Feeding Level on Insulin Secretion and Glucose Uptake in Sheep

A role for insulin in the regulation of nutrient partitioning in animals has been well recognized for many years9,10) Insulin secretion and glucose metabolism in ruminants are markedly influenced by the ratio of concentrate to roughage in their diets in general1,6,12). Compared to high roughage diets, high concentrate diets increased insulin blood levels and glucose metabolism in sheep and lactating cows3,4). Secretory insulin response to glucose injection has been reported to decrease in fasted and restricted-fed animals5,8,11) These results suggest that energy density in a diet and feeding level might affect ability of insulin secretion and insulin action on glucose uptake in the tissue in ruminants. However, the precise effect of energy density or feeding level on insulin secretion and action is not fully elucidated. The present experiment was carried out to determine the effects of dietary energy density (roughage to concentrate ratio) and feeding level on glucose-induced insulin secretion and insulin-induced glucose uptake in the whole body of sheep by glucose clamp techniques.