External appearance
• The basic external parts of a chicken include the comb, beak, wattles, ears, earlobes, eyes, eye rings,
wings, tail, thighs, hocks, shanks, spurs, claws, and toes.
• A chicken's head has several parts.
• One of the most prominent features on a chicken's head is the comb.
• Different combs are available. These are single, rose, pea, cushion, buttercup, strawberry and v-shaped.
• Chickens do not have external ears. The ear lobe is a specialized skin located below the ear. The color of the ear lobe depends on the breed of chicken as red or white.
Skeleton Structure
The chicken skeletal system has important differences to those of theier mammalian.
• The bones are lighter.
• Some bones (Pneumatic bones) act as part of the respiratory system.
• Some bones are medullary bones. They are important as source of calcium.
Digestive system
• The digestive system begins at the beak and ends at the cloaca.
• Beak-Esophagus- Crop- Preventriculus-Gizzard-Small intestine-Large intestine-Cloaca
The structure of the eyes in poultry and the difference from humans
• The vision system of poultry is entirely different from that of humans.
• These are……….
• According to previous studies, the light wavelength or light colour affects the behaviour, welfare and performance of the poultry.
• Therefore, since light management affects growth,
productivity, and behaviours, it is an important factor in poultry production.
• In studies on broiler chickens, green and blue light gave positive results on body weight while red light negatively affected weight gain.
• In laying hens, red and white light triggers the early development of ovaries and an increase in egg production.
• Furthermore, the highest mortality rate in laying hens occurred under blue light, whereas the lowest rate occurred under red light.
• In studies on roosters, the highest stimulation of sexual maturity was recorded under red and white lights.
• However, based on the rate of testosterone in blood, an increase was found in the use
of blue light.
Respiratory system
• The anatomy and physiology of the avian respiratory system differ markedly from mammalian systems.
• The first difference is the role of the lungs.
• Birds have an extensive air sac system.
