Estimation of Phenotypic and Genetic Parameters of Egg Quality Traits of Azerbaijan Native Hens

The egg quality is one of the most important economic factors for layers that are crucial for hatchability and marketing. Given the low number of egg quality traits records, one of the approaches in estimating phenotypic and genetic parameters is multi trait analysis. The aim of this study was to estimate the phenotypic and genetic parameters of west Azerbaijan native hens egg quality traits by multi-trait analysis. For this purpose, 2000 eggs of 14th and 15th generation of pedigree hens were purchased from west Azerbaijan native fowl breeding station and for measuring egg quality traits were transferred to laboratory. The genetic and phenotypic parameters of egg quality traits were estimated by multi-trait analysis using SAS and WOMBAT softwares. The generation-hatching time and storage duration in refrigerator had significant effect on egg quality traits. The mean of some egg quality traits were: egg weight 55.306 g±3.94, egg shape index 75.192±2.9, egg shell percentage 9.389 %±0.73, albumin percentage 60.160 %±2.49, yolk percentage 30.466%±2.35, yolk index 35.928±3.13 and yolk pH 6.442±0.13. The highest and the lowest coefficient of variance were calculated in air cell height and albumin pH, as 16.947 % and 1.366 %, respectively. The highest positive phenotypic correlation was observed between egg weight and egg volume (0.644), and the lowest one was observed between pH of albumen and yolk weight (0.004). The highest positive genetic correlation was observed between egg weight and egg shell surface area (0.999), the highest negative genetic correlation was observed between albumen percentage and yolk to albumen ratio (-0.994). The lowest positive genetic correlation was estimated between yolk index and yolk weight (0.002) and the lowest negative genetic correlation was evaluated between yolk index and dry matter of yolk (-0.005). The range of estimated heritability of studied egg quality traits were 0.212 (albumen percentage) and 0.015 (pH of albumen). Generally, the results indicated that the egg quality traits of Azarbaijan indigenous hens have relatively high phenotypic and genetic correlation, which in order to decreasing the cost of data recording, the number of recorded traits could be decreased. The heritabilities of egg quality traits were moderate to low that indicated the low progress with direct selection.