A Comparison of the Behavior of Injected Theelin in the Feathering of Thyroidectomized and Thiouracil Treated Brown Leghorn Capons

Abstract

The administration of estrogens in appropriate dosage to the cock or capon of the Brown Leghorn breed of fowl causes the normal male black pigments of regenerating breast feathers to be replaced by the female salmon in the anterior regions of the tract and by the female buff-stipple in the posterior regions of the tract.When Brown Leghorn cocks or capons are thyroidectomized (Greenwood and Blyth, 1929; Blivaiss and Domm, 1942), or when they are fed thiouracil at 0.5 percent levels (Juhn, 1944), the black male breast feathers become replaced by feathers of a reddish hue. This color, however, does not resemble the female salmon but is more closely comparable to the pigment normal to the marginal feather sections in the male dorsal tracts.Fraps and Burrows in 1939 described a series of observations on the effects of theelin injections upon the regenerating plumage of partially and of completely thyroidectomized .