Iodine Transfer and Concentration in the Prepartum Cow, Fetus, and Neonatal Calf

Abstract

Information regarding iodine transfer from dam to fetus has been obtained with 21 cows. Iodine concentration in the circulation of the fetus was observed to be over five times that found in the dam's plasma. Amnionic fluid contained more iodine than fetal plasma, but chorionic fluid iodine concentration was midway between maternal and fetal plasma. The inability of the fetus to excrete iodine in urine may be a major factor in the high calf/dam ratios of iodine at birth. After birth the disappearance rate of nonbound iodine from the calf exceeded that from the cow in the first two days after dosing. Percentage of the dose retained by thyroids and total radioiodine changes in plasma from birth or day of dosing were similar in dams and calves. © 1967, American Dairy Science Association. All rights reserved.