A. Forster et al., USE OF PHOTOMETRICALLY DETERMINED SHELL C OLOR PARAMETERS AS SELECTION CRITERIA FOR MARKETABLE BROWN-SHELLED EGGS, Archiv fur Geflugelkunde, 60(1), 1996, pp. 1-6
Based on data of five German random sample tests and pedigree data of
a commercial breeding programme, different parameters of shell colour
were investigated. In addition, a consumer survey was conducted to det
ermine preferences for specific shell colour. The shell colour paramte
rs L, a* und b*, electronically measured with a Minolta Chroma Meter,
agreed well with subjective scores assigned by an experienced person
before the measurements. Significant differences were found between st
rains, whereas differences among stations were much smaller. Heritabil
ities estimated from daughter-dam regressions and from site components
of hierarchical analyses of variance were in the range of .3 to .5 an
d reasonably consistent across lines, years, and methods of estimation
. Genetic correlations between pure-line and cross-line shell colour,
based on paternal half sisters in different environments, were very cl
ose to unity, correlations with other traits were weak. The consumer s
urvey indicated a preference fur intermediate shell colour and discrim
ination against extremely dark shell as well as tinted shells.