The Utilization of Free Amino Acid and Glucose Carbon by Sheep Pregnant with Twins

Using the constant infusion isotope dilution method, the rates of entry of glucose and free amino acids hare been measured in 4 Clun Forest ewes which were pregnant (133–139 days) with twins. The mean entry rate of free amino acids of 4.6±0.28 (4) mg./min./kg. was significantly higher than the calculated mean rate of 3.28±0.06 mg./min./kg. found for non-pregnant sheep eating equivalent amounts of protein (Ford & Reilly, 1969). The mean entry rate of 1.67 mg./min./kg. for glucose was similar to that of the non-pregnant sheep. The 19.9% of glucose which was derived from amino acids was not significantly different from the 13.7% derived by the nonpregnant animals. The 31% of amino acids oxidized to Co2 was significantly less than the 62% oxidized by non-pregnant animals (P < 0.005). The 40% of glucose oxidized by CO2 was significantly less than the 65% oxidized by non-pregnant animals (P < 0.05).