Mature Feathers Research Articles

Reflectance of Chicken Feathers in Relation to Sex-Linked Coloration

Reflectance spectra of down feathers from the heads of color-sexed chicks from broiler and layer strains were measured with a fiber-optic spectrophotometer. For both strains, the maximum divergence between sexes was at 350 nm (for broilers and layers respectively, t = 10 and t = 5, P<.005, n = 20) but significant divergence continued into the blue part of the spectrum (to around 500 nm). Mature feathers from Light Sussex (white), Rhode Island Red (red-brown), and Bantam (pale and dark bars on feathers) birds were measured as examples of deeper or more highly contrasting pigmentation. Divergences between spectra were found at higher wavelengths for the adult feathers than for color-sexed chick feathers (at 530 nm for white vs. red-brown, and around 700 nm for pale vs. dark bars.

Green shanks and adult mortality in chickens.

A mutation of recent origin in Cornell randombred Leghorn chickens causes the shanks to be colored green due to melanin-like deposition in the dermis, in contrast to normal yellow. Some pigment is often present in the mandibles and the mature feathers display an ashen cast. This mutant is determined by an allele, idc, on the sex chromosome. Excessive adult mortality with a high incidence of tumors, mainly hemangiomas, is associated with this gene--at least extending over a two-generation observation interval. Pullets receiving this mutant allele (idc) from their sire die at 2 to 3 times the rate of sisters, with yellow shanks, that carry the Id allele.

Intrafollicular Pressure in the Feather Follicle ,

A PREVIOUS report by Ostmann, Ringer and Tetzlaff (1963) indicated that anesthetics, sympathetic and parasympathetic blocking agents, and tranquilizing drugs caused the feather to loosen within its follicle. These workers did not clarify the exact role played by the muscles and wall of the feather follicle in feather release.An experiment using intrafollicular pressure as a measurement was designed to study the mechanism involved in the loose and tight states within the feather follicle. EXPERIMENTAL PROCEDUREMature S. C. White Leghorn hens were secured on an operating cradle which held them virtually motionless. A mature feather was randomly selected for studying intrafollicular pressure from either the femoral or caudal feather tract. With procaine used as a local anesthetic, one of the brachial veins was then cannulated for the subsequent injection of sodium pentobarbital.All feather shafts in the immediate area of the chosen feather were cut at the level of…

Feather Release by Scalding and Other Factors

A REPORT (Klose, Mecchi and Pool, 1961) on variations in feather-pulling force as related to time after slaughter, combinations of scalding and anesthetic, and feeding or injection of a tranquilizing drug included a literature review and discussed methodology. The present report adds information on the effects on feather release of scalding medium and temperature, radiant heat, brain sticking, and ante-mortem administration of pentobarbital. EXPERIMENTALFeather-pulling forces for chickens were measured as described in our previous report. All measurements were on mature feathers selected from a region along the midline of the back and extending from just below the junction of wings with body to about half way back to the tail. This area contains cape and back (contour) feathers.Effect of Heat on Feather Release. Preliminary experiments in which birds were scalded in 10-gallon and 50-gallon tanks, with and without circulation of the scalding medium, indicated that agitation of liquid …

Basic Mechanisms in the Differentiation of Pigment Cells

ABSTRACT Some of the basic mechanisms of cellular differentiation have been elucidated by an experimental analysis of the underlying factors and conditions which control the processes of differentiation of the pigment cell in the chick embryo. The pigment cell, owing to its singular capacity to synthesize melanin pigment granules, is an ideal cell for locating its site of origin and tracing its subsequent pathways to the skin and derivatives, the feather papillae. It has the further advantage that its specific behaviour is recorded as colour or colour pattern in the mature feather. In other words, by using the pigment-forming cell as a ‘marker’ many of its properties in time and space may be ascertained from the moment that it is first set aside as a specialized strain of cell until it reaches its ultimate position and visible expression in the growing feather papilla.