Estimation of multiple-trait genetic parameters and blup using different estimation methods for some egg traits in japanese quails [Japon bildircinlarinda bazi yumurta verim özelliklerine ait varyans unsurlarinin farkli tahmin yöntemleri kullanarak elde edilmesiyle çok özellikli genetik parametre ve blup tahminleri]

In this study,variance components are estimated using different methods for some egg yield traits in a japanese quail flock that is thought to be bred in terms of egg yield trait. in the study,sexual maturity age (eoy),sexual maturity weight (eoa),egg weight (ya) and egg yield (yv) traits measured on quails are used. variance-covariance components for these traits are estimated using reml (restricted maximum likelihood),gibbs sampling,ml (maximum likelihood) and mivque (minimum variance quadratic unbiased estimation) methods and the estimations of multiple-trait genetic parameters are obtained. the smallest error variance is obtained with gibbs sampling,which also gave the most unbiased results. blup values belonging to each quail are estimated by using the variance-covariance matrices,obtained from the four different methods,in the mixed model equations. heritabilities were estimated in the range of 0.28-0.38 for eoa,0.18-0.21 for eoy,0.36-0.43 for ya and 0.38-0.43 for yv. the highest positive genetic correlation was estimated between eoy and ya traits using all four estimation methods. spearman rank correlation values between blup values obtained using different variance-covariance matrices are obtained in the range of 0.90-0.99 for eoy,0.96-0.99 for eoa,0.97-0.99 for ya and 0.96-0.99 for yv. it was thought to be appropriate to use the variance-covariance components,which were obtained via gibbs sampling approach,in mixed model equaitons in estimation of breeding value.