Effects of egg shell color and storage duration on the external and internal egg quality traits of ATAK-S layer hybrids
The present study was conducted to investigate the effects of storage duration and egg shell color on external and internal egg quality traits. Eggs were obtained from 29-week--old ATAK-S layer hybrids reared in a traditional cage system. Storage durations were set as 0, 7, 14, 21 and 28 days. Shell color was classified as dark (59.00-67.99); moderate (68.00-70.99) and light (71.00-79.99) using the ΔΕ values of the eggs. The storage duration significantly affected the egg weight (P≤0.01), specific gravity (P≤0.01), breaking strength (P≤0.01), shell thickness (P≤0.01), shell weight (P≤0.01), surface area (P≤0.01), albumen index (P≤0.01), yolk index (P≤0.01), Haugh unit (P≤0.01), yolk color (P≤0.05) and albumen pH (P≤0.01). The egg shell color significantly affected the specific gravity (P≤0.01), breaking strength (P≤0.01), shell thickness (P≤0.01), shell weight (P≤0.01), albumen pH (P≤0.05) and albumen blood-meat spots (P≤0.05). The current findings revealed that the eggs should be transported to consumers as soon as possible, and further studies should be performed to darken egg shell colors. It was concluded that newly laid dark colored eggs had the best quality.