Characteristics of egg shell color in Nagoya breed
2004
Nakamura, A.(Aichi-ken. Agricultural Research Center, Nagakute (Japan)) | Noda, K. | Kino, K. | Kato, Y.
The present experiment was conducted to clarify the characteristics of egg shell color in Nagoya breed using three color values (L-value:brightness, a-value:redness and b-value:yellownees) measured by a reflection photo difference meter, and to investigate available indicators to improve the pink egg shell color effectively. The characteristics of egg shell color in Nagoya breed are summarized as follows; l. Since L-value of the blunt ends of eggs was low compared with that of the pointed ends, the darkness in the egg shell color was greater on the blunt ends than on the pointed ends of eggs. 2. There was a high negative correlation between L- and a-values, so it was suggested that the increase of darkness in the egg shell color would strengthen the redness. 3. Since L- and b-value increased with the age of the birds, the eggs laid by older birds was paler and more yellowish than those laid by younger ones. 4. Differences in the hue (b/a value) between optically reddish eggs and yellowish ones were found. 5. The superficial white deposits on the eggs decreased b-value markedly and increased a-value, so the coating appears to enhance the pink egg shell color. The present results showed that brightness (L-value) and hue (b/a value) could be useful indicators to improve egg shell color in Nagoya breed.
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