[Skin and plumage changes in domestic birds. II. Plumage changes--1]

Modifications of the plumage and specific feather malformations, as developed during the domestication process of different poultry species are described. The modifications include henny feathering, elongated feathers, ear tufts, muffs, and increased numbers of tail feathers. The greater part of these plumage modifications is generally of interest for exhibition poultry fancy. Several of the plumage abnormalities presented distinctly impair the normal species-typical way of life of the animals concerned. The spectrum of negative influences comprises disorders in social behaviour, loss of, or restrictions in typical plumage functions such as weather susceptibility, as well as disabilities of normal mobility. Finally, genetic defects and pathogenic predispositions are also connected with such plumage modifications.