Ducks are considered the second common strains of poultry in the world. In Egypt, more attention is focused lately on increasing meat production, particularly ducks which are considered the easiest domestic poultry (El-Soukkary, et al., 2005). Sudanese breed is considered a local breed and more favorable to the Egyptian consumer and more heat tolerant as compared to Muscovy duck (foreign breed)  (Tiguia et al., 2008). Bird skin is marked out by some specific mor­phological and physiological features. It does not have any sudorific glands, it is thin, elastic and its epidermis is both keratinized and lipogenic. Bird skin also acts as a sebaceous secretory organ (Stettenheim, 2000). The epidermis, the most superficial layer of the skin, is thinner in birds than in mammals (Spearman, 1966). The epidermis has two main layers – a superficial stratum corneum and a deeper stratum germinativium. The stratum corneum consists of flattened, keratinized cells. (Elias and Menon, 1991). The dermis is thicker than the epidermis and contains blood vessels, fat deposits, nerves and free nerve endings, several types of neuroreceptors, and smooth muscles that move the feathers (Lucas and Stettenheim, 1972).

Feathers are the most characteristic feature of birds, being complex epidermal structures (Lucas and Stettenheim, 1972). The diversity of functions and biological roles of feathers is also great. Most people think of feathers serving only for insulation of the body and for flight. However, feathers are also involved in protective coloration, signaling of all types (aggression, species recognition, flashing signals) between  individuals (Buhler, 1990). There are two basic types of feather: vaned feathers which cover the exterior of the body, and down feathers which are underneath the vaned feathers (Chandler, 1916). A typical vaned feather consisted of a main shaft, called the rachis. Fused to the rachis are a series of branches, or barbs; the barbs themselves are also branched and form the barbules. At the base of the feather, the rachis expands to form the hollow tubular calamus which inserts into a follicle in the skin. The basal part of the calamus is without vanes. This part is embedded within the skin follicle and has an opening at the base (proximal umbilicus) and a small opening on the sid; distal umbilicus (Mclelland, 1991). Feathers undergo wear and tear and are replaced periodically during the bird's life through molting. New feathers are formed through the same follicles from which the old ones were fledged. The presence of melanin in feathers increases their resistance to abrasion (Bonser, 1995).