ABSTRACT This study aims to evaluate the impact of different cage densities and ages on the growth performance and quality traits of eggs for Hy-Line laying hens. For this experiment, a total of 216 laying hens were divided into three groups, with 9 replicates each. The cage densities were 1353 cm2/hen, 677 cm2/hen, and 451 cm2/hen representing groups T1, T2 and T3, respectively. The results of the study showed that feed conversion ratio (FCR) was significantly improved and egg weights were significantly increased in hens with low cage density (p<0.05). Moreover, cage density significantly affected final body weight. At the end of the experiment, hens in group T1 were about 35 and 70 g heavier than those in groups T2 and T3, respectively. On the other hand, cage density had no significant (p>0.05) effect on egg shape index, yolk index, albumin index, Haugh unit, eggshell thickness, yolk color, and shape index. In conclusion, high space availability for hens had positive effects on feed conversion and egg weight.

ABSTRACT The effects of different supplemental oils on the performance, egg quality, and fatty acid (FA) profiles of eggs produced by 52 week-old Hy-Line laying hens were investigated. A total of two hundred ninety-two laying hens were assigned to three treatments with four replicates each, according to the source of oil supplemented to their diets: corn oil (CO), restaurant spent oil (RO), and a control diet (with soybean oil, SO) using a traditionally used oil in hens’ diets in local conditions. Egg production was not affected by the type of oil fed and did not change during the course of the study. Eggs mean weight were not affected by type of supplemented oil. A similar trend was observed for shell thickness, yolk heights, Haugh units, and albumen heights. The results demonstrated that both fatty acid C8:0 and C12:0, present in RO and SO respectively, do not appear in the egg yolk in any treatment. Incorporated RO significantly reduced (p<0.05) the percentage of unsaturated fatty acid in egg yolk as compared to the SO or CO. Conversely, replacing SO with high quality oil like CO in the feed of laying hens significantly enhanced (p<0.05) egg quality.