Estimation of the genetic variance components and the coefficient of heritability of milk yields in diary cattle population of Kastamonu province

In this study, milk yield sources of culture breed and culture breed crossbred dairy cattle in Kastamonu province were evaluated. For this purpose, 10.573 lactation records were obtained from 2206 members of the Cattle Breeders' Association of Turkey. 305 Day Milk Yield (DMY) was emphasized as a milk yield feature. Estimation of Heritability Grade and Genetic Variance elements were calculated with the help of computer program. Heritability 0,473-0,291 and 0,211 were estimated respectively in lactation order, which is one of the macro environmental factors affecting 305 DMY trait. Nested - hierarchical design was used and calculations were made with Computer Statistical Package Program. As a result; heritability calculated for milk yield can be used as selection criteria in breeding studies in dairy cattle population in Kastamonu.