A Study of the Secretion of Iodine in Milk of Dairy Cows, Using Daily Oral Doses of I131

Abstract
Daily oral doses of I131 to dairy cows resulted in maximum levels in the blood and milk at 7 days and in the thyroid after 10 days. From 5 to 10% of a daily dose appeared in the milk at equilibrium. Massive doses of NaI reduced the radioactivity of the milk by 1/2 and that of the thyroids by 2/3. The usefulness of this type of experiment for studying trace mineral metabolism was demonstrated.