Determining the Most Effective Variables for Egg Quality Traits of Five Hen Genotypes

Abstract

This study was conducted to determine the availability of internal and external egg quality traits as selection criteria in White and Brown layers. For this reason, internal and external egg qualities have been determined in the sample eggs of two commercial and three native layer genotypes between 28 and 72 weeks of age. External quality traits such as; egg weight, shape index, breaking strength, shell thickness and egg specific gravity; and internal quality traits such as; albumen height, Haugh Unit, albumen index, yolk height, egg specific gravity and yolk color has been measured in 276 eggs of each genotype. Principal Component Analysis was applied to determine the most explanatory variables of total variance. Breaking strength and shell thickness of external egg quality traits and albumen height, albumen index and Haugh Unit of internal egg quality traits have been found in order to the most effective parameters in the genotypes. Shell thickness and breaking strength of external quality traits, and albumen height and albumen index were determined in an alternative approach, which grouped the genotypes according to live weights. External quality traits; breaking strength and shell thickness were effective in both medium heavy and light genotypes. But albumen height and albumen index in medium genotype, albumen height and Haugh Unit in light genotype were found effective according to internal quality traits. In conclusion, selection can be possible by determining some traits to improve the external and internal quality traits which include egg weight. (C) 2012 Friends Science Publishers