EFFECT OF THIOURACIL ON THE JUVENILE PLUMAGES OF BROWN LEGHORN FOWL1

Abstract

THE INHIBITION of secretory activity with resulting hyperplasia of the thyroid which follows the administration of thiouracil was first reported in mammals (Astwood, Sullivan, Bissell and Tyslowitz, 1943; MacKenzie and MacKenzie, 1943). Later Mixner, Reineke and Turner (1944) showed significant weight increases of the thyroid in thiouracil-treated young chicks. Thiouracil administration to the adult Brown Leghorn capon was found to effect changes in feather pigment and structure (Juhn, 1944a), which are wholly comparable to modifications following thyroidectomy (Greenwood and Blyth, 1927, 1929; Parkes and Selye, 1937; Domm, 1942).