The Apparent Antagonism Between Vitamin A and Carotenoids in the Fowl

Abstract

Basal diets containing sources of carotenoid pigments were fed to groups of chickens during the first 6 wks. of life, after which the degree of shank pigmentation was detd. by matching with the Heiman-Carver color rotor. Chicks fed 9,000 or more units of vit. A/100 gm. of diet showed much less pigmentation than the controls, except for a group which was fed carotene. Chicks fed fish oil irradiated with U.-V. light for 16 hrs. to destroy vit. A showed no loss of pigmentation. Inhibition was not exclusively an intestinal phenomenon. Chicks with larger vit. A stores, as judged by liver analyses, accumulated pigment in their shanks at a much slower rate, suggesting that the effect is exerted in the blood or tissues or both.