A Comparison of Selected Quality and Compositional Characteristics of Brown and White Shell Eggs

Eggs were obtained from three strains of brown shell and three strains of white shell commercial layers during 12 28-day production periods. Forty-eight eggs were randomly selected from each of six strains during the last week of each period. Shell quality was measured by shell thickness, shell weight, percent shell, shell weight per unit surface area, and shell density. The average shell thickness of the white shell eggs (.390 mm) was significantly thicker than the brown shell eggs (.368 mm). The white shell eggs had a significantly higher average shell weight (5.62 vs. 5.30) and contained a significantly greater percentage of shell (9.35 vs. 8.65) than the brown shell eggs. The white shell eggs had a significantly greater shell weight per unit surface area (72.97 vs. 78.43 mg/cm2) than the brown shell eggs.