Seven Vital Trace Minerals for Cattle | Purina Animal ...
Iodine in cows Iodine is deficient in soils of plants across much of the Northern U.S. in the Goiter Belt. In addition, certain plants contain goitrogens that inhibit the use of iodine and increase its requirement. The estimated iodine requirement for growing cattle is .5 ppm with a tolerance of 8 to 50 ppm.