The Relation of Serum Xanthophyll in Chickens to the Pigmentation of Their Shanks

POULTRY consumers in some areas prefer poultry having an abundance of yellow pigment in the skin and shanks. Palmer (1915) reported that xanthophyll supplied by the diet is the principal pigment in egg yolk, body fat, blood plasma and skin, especially of the shanks and claws. Several methods have been developed for the evaluation of the degree of pigmentation in the shanks of birds by comparing the color of the shanks with known standards. Brown (1930) used the Bradley color top to measure shank color. Differences in pigmentation were visible after one week in chicks hatched from eggs where the hen’s diet contained pimiento. Maw (1939) determined the color of the body fat, skin, and shanks by comparing them with carotene. Ringrose, Norris and Heuser (1939) compared the intensity of the shank color with a series of glass tubes colored with various shades of yellow which had been used in . . .