Published on Sept. 20, 2019
Eggshell color is a major trait in the HG layer breeding program for many years. It is key to score all individual eggs with an high accuracy. To avoid any subjective scores ISA has invested long time ago in special devices which have been developed for that purpose.
In the past years it was common to use the reflectometer to measure shell color. This device works by taking a percentage between black (0%) and white (100%). For most world brown egg markets, a value of 25-40% is usual. Those values were the one HG used to communicate on.
Reflectometer is not the only device used within the R&D program. HG layer division collects also data based on chromameters. During the past years, measurements have been done with the Minolta CR300, CR400 and CM600d. Those chromameters provide 3 information:
L: brightness (black/white)
a: chroma value (green/red)
b: chroma value (blue/yellow)
Compare to the reflectometer, chromameter brings more detail of the eggshell color. To express easily the eggshell color
In the world wide community working on color (meat color, vegetable color,…), Lab is now the common way to measure it. This is why HG layer division has decided to express eggshell color with Lab values.
This value is the result of the following equation Lab= L-a-b (lower is the value, darker is the egg). But the range of the Lab is not anymore then same than the reflectometer measurement.
Associated Lab values