ADRENALECTOMY IN THE GOAT REPLACEMENT THERAPY AND THE MAINTENANCE OF LACTATION

Abstract

SUMMARY The mean survival period of twelve goats after adrenalectomy was 7·8±1·2 days. Adrenalectomy resulted in a progressive rise in the concentration of K and a fall of Na in the plasma. In the lactating goat there was a rapid inhibition of milk secretion and the concentration of K in the milk fell, while that of Na rose slightly as the yield dropped. Partial to complete maintenance of lactation was achieved in five lactating goats after adrenalectomy by implanting tablets of cortisone (or cortisone acetate) and deoxycorticosterone acetate (DCA), a daily absorption of at least 6–12 mg cortisone (or its acetate) and 2·5 mg DCA being required. DCA was the more critical component of the combination. During replacement therapy, when the daily milk yield had become relatively steady, the composition of the milk (fat and solids-not-fat percentages) and the Na and K concentrations in the milk were within the pre-operative ranges, but during the periods of adrenal insufficiency, when the milk yield declined, there was a concomitant rise in milk-fat percentage and a fall in milk K. These changes, however, also occurred when the milk yields fell from other causes and so they may not be directly attributable to the lack of adrenal steroids.