Research Information System
ANIMALS, vol.11, pp.1-15, 2021 (SCI-Expanded)
Consumer interest in buying eggs from animal welfare-friendly systems with outdoor
access is increasing, leading to an increase in the need for knowledge on genotypes suitable for
free-range systems. Two Turkish laying hen genotypes, Atak-S (brown, n = 210) and Atabey (white,
n = 210), were reared in a free-range system from 19–72 weeks of age, and their suitability for the
system was assessed based on laying performance, egg quality, and yolk fatty acid profile. Mean
hen-day and hen-housed egg production were found to be higher in Atabey than Atak-S (p < 0.01).
The brown eggs from Atak-S hens tended to be heavier than the white eggs from Atabey hens
(p < 0.01). Brown eggs obtained from Atak-S hens had a stronger shell structure (p < 0.01), while
white eggs from Atabey hens had higher mean yolk index, albumen index, and Haugh unit than
brown eggs (p < 0.05). At 56 weeks of age, total saturated fatty acid content in yolk was higher in
white eggs than in brown eggs (p < 0.01). These findings related to genotype could help free-range
egg producers in their choices for more profitable production and for meeting consumer demands on
egg quality and egg yolk fatty acid levels.