A New Objective Measurement of Eggshell Color.

A new technique for obtaining objective measurements of eggshell color was explored using the Hunter Lab Colorimeter D25A-9 and the Minolta Chroma Meter CR-200. A total of 1,299 eggs from 161 hens in five lines were measured on these two color meters. Measurements for individual eggs were highly repeatable (P>.25); differences between hens were significant (P<.005); and yolk shade affected the measurement of shell color in white-tinted eggs but not in brown eggs. Measurements with the Minolta meter agreed with visual color classification regardless of egg size; however, when the Hunter meter was used, agreement between visual classification and the meter measurement was reached only when eggs of a uniform size were used. Compared with the Hunter meter, the Minolta meter has more standardized reading values, more descriptive color scales, and is portable.