Veterinary World (Oct 2013)
Genetic analysis of egg quality traits in White Leghorn chicken
Abstract
Aim: The present study was undertaken to estimate the genetic parameters and to assess the inheritance pattern of egg quality traits in White Leghorns. Materials and Methods: Data on 480 eggs produced by 40 week old pullets of 4 genetic groups were used for studying egg quality traits. Heritabilities and correlations were estimated by full sib correlation method using Mixed Model Least Squares and Maximum Likelihood (LSMLMW) computer program. Results: The egg weight, haugh unit, yolk index, albumen index, yolk weight, albumen weight, shell weight and shell thickness ranged from 50.01 ± 0.48 to 53.89 ± 0.43 g, 65.38 ± 0.92 to 80.98 ± 1.01, 0.341 ± 0.003 to 0.353 ± 0.003, 0.056 ± 0.002 to 0.087 ± 0.002, 14.16 ± 0.13 to 15.58 ± 0.12 g, 30.92 ± 0.39 to 33.18 ± 0.39 g, 4.32 ± 0.05 to 5.12 ± 0.05 g and 0.336 ± 0.003 to 0.376 ± 0.003 mm, respectively. Heritability estimates for egg weight, yolk index, albumen index and albumen weight ranged from low to medium while those of haugh unit, yolk weight, shell weight and shell thickness ranged from low to high. The genetic and phenotypic correlations of egg weight with other egg quality traits except shell quality traits were mostly positive and moderate to high. High positive genetic and phenotypic correlations between haugh unit and other traits were observed. Genetic correlation of yolk weight with albumen weight was positive while that with shell quality traits was mostly negative. Shell weight was positively correlated with shell thickness. Conclusion: Significant genetic group differences were observed for various egg quality traits studied. The heritability estimates for different egg quality traits were low to moderate. The association among egg quality traits was positive in general. [Vet World 2013; 6(5.000): 263-266]
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