Correlation between Internal and External Egg Quality Indicators in the Early Phase of Hy-Line Brown Laying Hens

This study investigated correlations between egg quality indicators to identify external egg quality traits to predict internal egg quality using non-destructive and convenient measurements. Thirteen indicators, including Haugh unit, albumen height, eggshell breaking strength, eggshell thickness, eggshell color (CIE L * , CIE a * , CIE b * ), and reflectivity value, egg weight, egg length, egg width, shape index, and yolk color, were investigated. A total of 180 brown eggs were obtained from one 27-week-old flock of Hy-line brown-laying hens raised in a cage system. Correlations were evaluated using Pearson's correlation coefficient (r). The results showed strong correlations between Haugh unit and albumen height, eggshell color CIE L * and reflectivity, egg weight and width, egg weight and length, eggshell color CIE L * and CIE a * , eggshell color CIE a * and reflectivity, and shape index and egg length ( P <0.001). Moderate correlations were observed between eggshell breaking strength and eggshell thickness, eggshell color CIE a * and CIE b * , and shape index and egg width ( P <0.001). Eggshell color CIE L * was correlated with eggshell breaking strength ( P <0.01), and eggshell color CIE a * was correlated with Haugh unit, albumen height ( P <0.01), and eggshell breaking strength ( P <0.001). The present study showed significant correlations between eggshell color and other quality indicators. Thus, this study suggests that eggshell colors based on reflectiveness and the CIE L * a * b * value can be used to estimate the