Feather Phaeomelanin Intensity in Buff Orpington, New Hampshire and Rhode Island Red Breeds of Fowl: 1. Age, Sex and Feather Growth Effects ,

Abstract

RED and buff feathers are commonly found among the many varieties and breeds of domesticated poultry. The pigments producing the range of buff-red colored feathers were first called phaeomelanins by Görnitz (1923), thus separating them from the black or eumelanin pigment. Areas of the plumage devoid of eumelanin may either contain phaeomelanin or be white due to the absence of visible amounts of pigment. The latter alternative in columbian or wild type patterns is referred to as silver and was shown by Sturtevant (1912), Davenport (1912) and Dunn (1922 and Dunn (1923) to be controlled by a single pair of sex-linked alleles, silver (S) and gold (s+). All breeds charaterized by the presence of phaeomelanin appear to be homozygous for the s+ gene.Feather phaeomelanins are deposited in the keratinous structure of the feather in the form of spherical and oval granules (Lloyd-Jones, 1915; Jeffrey, 1934; Bohren et al., 1943; and…