The Effect of the Ration Upon Iris Color of Single Comb White Leghorns

EYE color in the domestic fowl has received increasing attention in the past few years. This interest has resulted from gross and histological studies showing that many of the abnormalities of the eye are due to the ocular forms of lymphomatosis. The work of Lee and Wilcke (1941) and others has led to the general recommendations that birds showing any fading of pigment and any irregularity of the pupil, should be discarded. In some studies, there has been mentioned the disturbing comment that strain and dietary factors may cause a fading or bleaching of pigment from the iris. Unfortunately, the literature contains few critical studies of iris color as affected by heredity or nutrition. Recently, Hollander and Owen (1939), by chemical tests, demonstrated that the yellow pigments in the iris of the domestic fowl were probably carotene and xanthophyll, the same pigments as in green feedstuffs and yellow corn. Previously, . . .