The Defeathering Effect by Scalding in Chickens Follows Their Intrinsic Dermal Histologies

Area of Science:

• Animal Science
• Histology
• Poultry Science

Background:

• Understanding broiler and native Red-Feather (RF) chicken skin histology is crucial for optimizing poultry processing.
• Defeathering by scalding involves thermal effects on skin and feather structures.

Purpose of the Study:

• To compare skin histology and feather characteristics between broilers and RF chickens.
• To investigate the impact of scalding on skin structure and its relation to defeathering efficiency.

Main Methods:

• Histological examination of skin samples (fresh, dehydrated, fixed) from broilers and RF chickens.
• Analysis of collagen content, skin thickness, and feather follicle morphology.
• Assessment of skin tissue denaturation and structural integrity after soft and hard scalding.

Main Results:

• RF chickens possess thicker dermal layers with more collagen and a compact architecture, but thinner hypodermal layers in specific areas.
• RF chickens showed differences in feather calamus dimensions and a more robust follicle sheath.
• RF chicken skin demonstrated higher resistance to thermal denaturation and structural disintegration during scalding, with narrower feather sheath-follicle gaps.

Conclusions:

• Intrinsic skin histology, particularly the interaction between feather calamus and follicle sheath, dictates resistance to thermal denaturation during defeathering.
• The defeathering process is primarily influenced by the chicken's skin structure rather than feather properties alone.
• Breed and age-related histological differences significantly impact thermal resistance in poultry processing.