Different selection strategies for improvement of egg quality and hatching traits of Japanese quail

Abstract

Abstract The present study evaluated the effect of different selection strategy (SS) on egg quality and hatching traits in four closed-bred flocks (CBF) of Japanese quail, already selected for higher 4-week body weight, and at three parental ages (PA). A total of 1620 eggs obtained from 540 quail breeders from the four CBF and three PA were used and the effects of three SS were investigated in relation to egg quality traits. For evaluation of SS on hatching traits, a total of 3240 quail hatching eggs were subjected to break out analysis. A completely randomised design in a factorial arrangement of 36 treatments with 9 replicates was applied. Treatments consisted of three selection strategies [pedigree based (PB), mass selected (MS) and random bred control (RBC)], four closed-bred flocks [Major (M), Kaleem (K), Saadat (S) and Zahid (Z)] and three parental age groups [10 (Y), 12 (P) and 14 (O) weeks]. Egg characteristics (egg weight, yolk index, Haugh unit score and shell thickness) and hatching traits (hatchability, infertile eggs, early embryonic mortality, late embryonic mortality and chick weight) were evaluated. Pedigree based selection significantly influenced hatchability, fertility, infertile eggs, early embryonic mortality, late embryonic mortality and chick weight. However, the results of different closed-bred flocks and age groups did not differ significantly. Regarding egg quality traits, significant effects of pedigree selection and closed-bred flocks were observed on yolk index and Haugh unit score. Age had significant effect on egg weight, yolk index, Haugh unit and shell thickness. It was concluded that pedigree-based selection among different age groups and closed-bred flocks had pronounced effects on egg quality and hatching traits in Japanese quail.