Phenotypic Correlation between the External and Internal Egg Quality Traits of Pharaoh Quail Reared in Derived Savanna Zone of Nigeria

Abstract

This study was aimed at determining the internal and external quality traits of Japanese quail eggs as well as the phenotypic correlation between these traits. A total of 360 eggs collected between the first six weeks of the laying circle were used for this study. Data obtained for external egg quality traits: egg weight (EW), egg length (EL), egg breadth (EB), shell weight (SW), shell thickness (ST)) and internal egg quality traits yolk weight (YW), yolk length (YL), yolk height (YH), yolk index (YI), albumen weight (AW) and albumen height (AH)). The mean values related to EW, EL, EB, SW and ST were as 8.1g, 2.98cm, and 2.43cm, 0.94mm, and 0.14mm respectively. YW, YL,YH, YI, AW and AH were found respectively as 2.29g, 2.10cm, 0.79cm, 0.39cm, 4.95g, and 4.96mm. Significant (P < 0.01) positive correlation existed between the EW against the EL, EB and SW. Also significant (P< 0.05) positive correlation was between EL and EB. Significant (P < 0.01) positive correlation existed between the YW and YL, YH and YI with significant (P < 0.05) positive correlation between YI and AH. The results suggest that the egg weight is a possible determinant of most of the external egg quality traits of quail egg. Egg weight therefore, is a good determinant of egg shell quality in quail egg and changes all occurred in internal egg quality of quail.

Keywords: Pharaoh quail eggs, external quality trait, internal quality trait, phenotypic correlation, derived savanna zone