What are the main factors affecting the color of eggshells?

What are the main factors affecting the color of eggshells?‌

The Primary Factors Influencing Eggshell Color‌

‌Genetic Factors‌
Different chicken breeds have inherent variations in eggshell pigment synthesis capabilities. For example:

Brown-shell layers produce reddish/brown eggs

White-shell layers produce white eggs

‌Hen Age‌
Hens over 40 weeks old experience declining pigment synthesis capacity, leading to gradually lighter eggshell color.

‌Nutritional Status‌

Deficiencies in vitamins A/B, calcium, or vitamin D3 can cause pale shells or white spots

Dietary carotenoids (added to feed) mainly affect yolk color with minimal impact on shell color

‌Health & Stress‌

Intestinal diseases or reproductive infections (e.g., Newcastle disease) reduce pigment absorption efficiency

High temperatures, noise, and other stressors disrupt pigment deposition, resulting in generally lighter shells in summer

‌Environment & Management‌

Water quality and light intensity may indirectly influence pigment synthesis

Temporary color changes may occur during vaccination or antibiotic administration

Key Features of ST-17 Eggshell (Meat Products) Colorimeter‌

‌Automatic Calibration‌ with over 30 measurement parameters and 26 standard light sources

‌Gloss Removal‌ for accurate color measurement

‌30+ Indicators‌ including whiteness, yellowness, etc., with high repeatability

‌Metrology Institute Certification‌ compliant

‌Eggshell Color Classification & Formation‌

Eggshell colors range from white, light brown, brown, dark brown to blue-green. Consumer preferences vary: some favor red-shelled eggs, others believe blue-green shells indicate higher nutritional value.

Color formation occurs during the final stage of egg production in the hen's reproductive tract:

‌Pigment Secretion‌: Uterine epithelium deposits pigments like protoporphyrin (brown) and biliverdin (green).

‌Determinants‌:

‌Genetic Factors‌: Primary determinant of pigment type.

‌Diet & Health‌: Secondary factors influencing pigment intensity.

‌Hen Age & Condition‌: May cause color variations over time.