INTRODUCTION INVESTIGATION on the formation and thyroidal potency of synthetic iodinated proteins dates back to the latter part of the nineteenth century, following Baumann’s discovery of iodine in organic combination in the thyroid gland in 1895. Recently, Reineke and Turner (1943) have reported improved techniques for the synthesis of iodocasein which shows a high degree of thyroidal potency and have carried out investigations to determine if this material influences various productive processes in domestic animals. Comparisons have been made of the amounts of iodocasein required to produce a lactation response in dairy cattle when administered orally or injected subcutaneously. The results indicated that iodocasein is utilized only slightly when given orally. In sheep, only 5 per cent as much iodocasein was required by subcutaneous injection to bring about a standard weight loss as when given orally. When the iodocasein was placed directly in the abosmasum through a permanent cannula in order to bypass...
Read full abstract