Eggshell color is a major egg quality criterion and an important trait in Novogen’s breeding program. An objective and individual measurement provides a valuable tool for our selection program. The aim is to accurately quantify color differences between eggs produced by individuals within the same line and to monitor these differences over time.
Measuring Eggshell Color Using a Chroma Meter
Eggshell color is measured using a chroma meter, enabling an objective and reproducible evaluation. This instrument analyzes the light reflected from the shell surface and provides colorimetric coordinates according to the CIELAB (or Lab*) system, which is widely used in the food and industrial sectors.
Measurement Method
The measurement is performed directly on the eggshell surface using a chroma meter. The device emits standardized light onto the egg and then measures the reflected light. Results are expressed through three parameters: L*, a*, and b*.
- L* indicates the lightness or darkness of the shell color.
- a* describes the color position on the green–red axis.
- b* describes the color position on the blue–yellow axis.
Quantifying Individual Differences
Even within a genetically homogeneous line, hens exhibit individual differences in their ability to deposit the pigments responsible for eggshell coloration. These variations can be difficult to assess visually, particularly when the differences are subtle.
The L*, a*, and b* parameters provide an objective and reproducible description of shell color, enabling fine discrimination among individuals within the same population. Instrumental measurement is therefore more precise and reliable than visual scoring.
In the context of genetic selection, this level of precision is essential for identifying breeders that exhibit the desired shell color characteristics.
Monitoring Color Changes with Age
Eggshell color changes throughout the productive life of a hen. In brown-egg layers, a gradual decrease in color intensity is commonly observed as hens age.
Taking measurements at different stages of production makes it possible to assess not only the level of coloration but also everyone’s ability to maintain shell color over time, a particularly important criterion in breeding programs.
Breeder’s Perspective
Eggshell color is one of the quality traits monitored in our breeding program. Eggs from pure lines are individually measured throughout the production period.
Generation after generation, the objective is to improve the intensity and uniformity of shell color in NOVOgen Brown hens. As this trait has good heritability, the genetic progress achieved has been significant. The use of genomics in recent years has further accelerated these improvements.
For NOVOgen White hens, the breeding program focuses on maintaining a high-quality pure white shell color, as the intensity of whiteness can also vary over time.
