An isotope dilution method of [U-13C]glucose with open circuit calorimetry was applied to determine the effect of dietary crude protein (CP) intake 5.6, 7.7 and 10.8 g/kg BW0.75/d on turnover and oxidation rates of plasma glucose in four adult sheep. Isotopic enrichments of plasma [U-13C]glucose and exhaled 13CO2 were determined for calculating the parameters of plasma glucose metabolism. Turnover and oxidation rates of plasma glucose did not change with dietary CP intake levels. It is likely that in adult sheep, plasma glucose metabolism is not influenced by dietary CP intake, when sufficient digestible energy is supplied.
Glucose metabolism, dietary protein intake, isotope dilution method, sheep
