Changes in External Egg Traits of Chickens during Pre- and Post-Molting Periods

481 fresh fertilized eggs of three Kurdish local chickens (Black with brown neck, White with shank feathering, and White with non-feathering shank) were collected at pre-molting (355 eggs) and post-molting (126 eggs) stages to evaluate external egg traits. A venine caliper was used to determine the length and breadth of eggs to calculate Shape index. Results indicated that egg weight increased in all genetic groups (P < 0.05) at post-molting stage compared with pre-molting stage. There was a significant difference in egg length between pre- and post-molting periods from the black chicken with brown neck and white chicken with shank feather, but not from the white chicken with non-feathering shank. Also, egg breadth was similar between pre- and post-molting periods from black with brown neck and white with shank feather, but was different from white with non-feathering shank. Shape index was also similar between pre- and post-molting periods for white with shank feather, but were significantly different (P < 0.05) for black with brown neck and white with non-feathering shank. The results of this study indicate that egg external traits improved during post-molting period than pre-molting, and variations between egg layers for external traits could be due to the genetic makeup.

Keywords:

Local chicken , Natural molting , Egg external trait