Source of Iodine in Salt Affects Protein-bound Iodine Content of Bovine Blood Plasma

Abstract

Feeding I in the form of cuprous iodine and 3,5-diiodosalicylic acid in trace-mineralized salt (0.0074% I) apparently caused an elevation of protein-bound iodine (PBI) in blood plasma. The salt was fed as 1% of the concentrate which totalled 4 lb./heifer daily. The PBI of 12 dairy heifers averaged 19.9 [mu]g/100 ml of plasma when fed this trace-mineralized salt and dropped to 3.6 [mu]g within 7 days after removal of all I supplement. When the trace-mineralized salt was fed again, the PBI levels gradually increased to an average of 12.8 [mu]g in 14 days. The feeding of similar amounts of a trace-mineralized salt containing KI as the I source produced PBI levels averaging 4.1 [mu]g. It is suggested that the 3,5-diiodosalicylic acid combines with some compound (s) in the blood to give the high PBI values.