Iodine

Abstract

Effects of iodine deficiency in the dairy cow other than the birth of goitrous calves have not been clearly delineated. Additional evidence is available that lactational response, reproductive performance, and other possible functions are altered during periods of low iodine availability. Dairy cattle which do not receive supplemental iodine may not be receiving the minimum iodine needed, even in areas not considered in the goiter belt. The National Research Council iodine recommendations are probably minimal rather than providing 3.5 times the requirements as originally calculated. The presence of large amounts of goitrogenic substances, such as soybean meal, and the iodine content of milk were not considered in calculating the requirements for dairy cattle. High-producing cows receiving high concentrates containing soybean meal or other iodine-binding agents may have need for additional iodine. © 1970, American Dairy Science Association. All rights reserved.