Genetic correlation between egg quality traits

Genetic correlation coefficients between egg quality traits were studied using fifty- six harco pullets raised under standard management practices. The estimates were carried out at 22-week, 26-week, 30-week and 32-week of age. Egg quality traits studied include egg weight (EW), shell thickness (ST), haugh unit (HU), yolk index (YI) and shape index (SI). Zero to slight negative correlation coefficients was observed between EW and HU, EW and YI, EW and SI, ST and SI, and HU and YI. This implies that selection for any of the character entails minimal retrogressive response on corresponding trait. Conversely, zero to slight positive correlation coefficients was recorded between EW and SI, SI and YI, and HU and SI. Again, selection for any of this character will bring about a slight genetic gain on the corresponding trait. Furthermore, the study maintained that the genetic correlation coefficients between egg quality traits are independent of the laying age, and for faster genetic response in egg quality traits, independent culling method. Again, since genes governing the expression of these egg quality traits appear to be independent of each other, it is possible to localize, isolate and intersperse these genes simultaneously in foundational poultry lines using biotechnological tools for faster genetic gain.

کلیدواژه ها:

Correlation ، Egg quality traits ، Genetic gain and selection