Variations in the Phaeomelanin Intensity of the Head and Neck Feathers of Gold Columbian Chicks1

ABSTRACT Segregations of a down-feather color variant are described in crosses of gold Columbian patterned fowl. The down-feathers of the head and neck of gold Columbian chicks are usually of the same brown-red color intensity as are the body down-feathers, whereas with this color variant, the down-feathers of the head were light buff in color, contrasting sharply with the much darker body color. From the segregation ratios, a polygenic mode of inheritance was proposed to account for the inheritance of this trait. These same genes also seemed to cause a significant intensifying effect on the postjuvenile feather phaeomelanins, which was in direct opposition to their pigment suppressing action in the down. POULTRY SCIENCE 52: 831-835, 1973 T N THE domestic fowl, chicks of the * ~ gold Columbian plumage-type are gen-erally, on an individual chick basis, of a uniform dorsal surface coloration. They do differ greatly, however, in their overall intensity of feather phaeomelanin pig-mentation from one breed to another. A distinct variation of the usual uniform dorsal surface coloration was observed among the progeny from F2 crosses be-tween three gold Columbian type breeds— Buff Orpington, New Hampshire and Rhode Island Red. The variant type chicks, to be referred to hereafter as "light, " had a light buff colored head and neck which was in marked contrast to the much darker red of the back (Figure 1). Typically, the gold Columbian type chicks, which will be referred to as "dark " here-after, had a dorsal surface coloration in which the back, neck and head were all of a uniform red intensity. This study was conducted to determine if this observed difference in head and neck coloration of gold Columbian type chicks had a heritable basis, and to deter-mine if there was any relationship between these two chick coloration phenotypes an