Effect of Insulin Administration on Blood Acetate and Feed Intake of Sheep1

Two experiments were conducted with sheep to investigate the effect of insulin on plasma acetate and on feed intake. In experiment I, plasma acetate of four ewes was measured at 0, 30, 60, 120 and 240 min. following intravenous administration of 0.0, 0.25 and 0.S0 units of insulin per kg body weight. When ewes were fed at the time of injection, both insulin dosages significantly reduced plasma acetate at 30 minutes. In ewes which were fasted for 20 hr., both insulin dosages significantly lowered plasma acetate levels at 30, 60 and 120 minutes. Subcutaneous insulin injections produced a similar depression in plasma acetate of fasted sheep. In experiment II, three trials were conducted to study the effects of insulin administration on feed intake of wethers. Insulin injections, which reduced blood acetate, a proposed regulator of feed intake in ruminants, did not stimulate feed intake under the experimental conditions of these trials