摘要：This study was carried out a total of 4960 lactation records collected from 2004 to 2012 reared at Cattle Breeders Association of Turkey were used to estimate the variance components, breeding values, heritability and repeatability to 305-day m ilk yield (305 DM Y), lactation length (LL), dry period (DP), service period (SP) and calving interval (Cl). Data were analyzed using multiple trait derivative free restricted maximum likelihood (MTDFREML) fitting an animal model. The heritability of 305 DMY, LL, DP, Cl and SP were estimated as 0.22 (士<0.001); 0.14 (士0.035); 0.01 (士0.011); 0.01 (士<0.001) and 0.05 (士0.013) respectively. It was found that the m ilk productions of the cattle in the study can be used as selection criteria for development of effective genetic trend and m ilk productions in the investigated dairy farms can be im proved.
