The aim of the present study was to estimate (co) variance components for birth weights of Karacabey Merino lambs. The model fitted included direct genetic, maternal genetic, and direct-maternal genetic covariance and maternal permanent environmental effects. Data and pedigree information of the Karacabey Merino sheep used in this study were collected at the Marmara Animal Breeding Research Institute from 1998 to 2002. Variance components for birth weights were estimated by the MTDFREML. A direct heritability estimate of 0.08 and a maternal heritability estimate of 0.05 were obtained for birth weight. The maternal permanent environmental effect was significant. The estimate of the direct-maternal genetic correlation was found high and negative. In conclusion, maternal effects on birth weight of Karacabey Merino lambs were significant and need to be considered in any selection program undertaken in this breed.

The aim of the present study was to estimate (co) variance components for birth weights of Karacabey Merino lambs. The model fitted included direct genetic, maternal genetic, and direct-maternal genetic covariance and maternal permanent environmental effects. Data and pedigree information of the Karacabey Merino sheep used in this study were collected at the Marmara Animal Breeding Research Institute from 1998 to 2002. Variance components for birth weights were estimated by the MTDFREML. A direct heritability estimate of 0.08 and a maternal heritability estimate of 0.05 were obtained for birth weight. The maternal permanent environmental effect was significant. The estimate of the direct-maternal genetic correlation was found high and negative. In conclusion, maternal effects on birth weight of Karacabey Merino lambs were significant and need to be considered in any selection program undertaken in this breed.