The effects of naked neck and frizzle genes on the fertility, hatchability, egg quality and pterylosis of locally developed commercial layer parent lines.

Abstract

In this study, the effects of feather cover and feather colour genotypes and their interactions on the fertility, hatchability, external and internal egg qualities of 24-week-old locally developed layer parent lines were assessed. A 2 x 3 factorial experiment laid out in a randomized complete block design of two feather colour variants (brown and white) and three feather cover genotypes (naked neck, frizzle and normal feather) was used for this study. A total of 3,196 eggs from 360 layers of three feather genotypes were set for incubation. Data on fertility, hatchability, egg quality characteristics and chick weight were analysed using the PROC MIXED of SAS and differences between means were separated using LSD at 5% probability level. Percentage fertility of eggs of naked neck and frizzle feathered birds were significantly higher (p<0.05) than those in the normal feathered birds (71.98%, 70.29% vs 63.17%). Eggs of frizzle feathered birds (76.81%) recorded higher (p<0.05) hatchability than those of the naked neck (65.07%) and normal feathered birds (59.64%). Feather cover genotype had no significant difference (p>0.05) on weight of day-old chick. Feather colour genotype significantly (p<0.05) influenced egg weight but not other external egg characteristics. Feather cover and colour genotypes had significant (p<0.05) effect on some of the internal egg qualities. Follicle numbers in the ventral, dorsal and lateral regions were lower (p<0.05) in the naked neck birds relative to the frizzle and normal feathered birds. The incorporation of F and Na alleles into layer parent stocks in hot humid areas could improve fertility, hatchability and egg quality traits of birds.