R. Bras. Zootec.. 01/Feb/2017;46(02):105-12.
Influence of eggshell colour on egg yolk antibody level, incubation results, and growth in broiler breeders
This study was performed to determine the effect of shell colour in eggs acquired from Ross-308 broiler breeders on the interior and exterior quality of the egg, the antibody content of the egg yolk, and growth performance. The shell colours of a total of 1350 eggs were classified, using a colorimeter, into three groups: dark (E<64), medium (E:64.00-67.00), and light (E>67). The difference between groups with respect to egg weight, shape index, shell weight, and Haugh unit value was significant. Egg yolk antibody content (IgY) was 6.658 mg/mL in the dark colour group, 5.130 mg/mL in the medium colour group, and 5.242 mg/mL in the light colour group. Among incubation characteristics, the fertility rate as, in order, 94.66%, 92.14%, and 87.92% in dark, medium, and light shell colour eggs, and the hatchability was 87.00%, 84.28%, and 80.57%, in the same order. No significant difference was observed between groups with respect to hatchability of fertile eggs and embryonic mortality rates. No significant difference was observed between groups for live weight, feed intake, and feed conversion ratio either. The eggshell colour has an effect on yolk antibody content and on the hatchability, but it has no influence on hatchability of fertile eggs, Haugh unit and growth performance.