Protein-Bound Iodine Levels in Dairy Cattle Plasma

Abstract

A digestion-distillation procedure for the detn. of plasma protein-bound iodine (PBI) was applied to 177 dairy cows and calves of various breeds. Calves under 48 hrs. of age averaged 13.7 [mu]g.%, while those between 2 days and 12 mos. averaged 7.2 [mu]g.%. Heifers between 1 and 2 yrs. of age averaged 6.2 and older animals 4.6[mu]g.%, respectively. A group of Jersey and Holstein cows maintained in the same herd averaged 4.97 and 4.84[mu]g.%. Seasonal variations were significant only for the Holstein cows. Both breeds were lowest in Nov. Jersey cows from another herd and sterile cows were significantly lower than animals in the college herd.