Estimation of Genetic and Phenotypic Trends, Heritability and Repeatability for Some Milk Production Traits of Holsteins

Abstract

The purpose of this study is to estimate the trend components and genetic parameters of 305-day milk yield and lactation length in Holstein Friesian Cattle. The phenotypic, genetic and environmental trends for 305 days milk yield and lactation length were found to be -23.59 kg/year and -0.486 days/year, 7.99 kg/year and -0.49 days/year, -31.58 kg/year and -0.976 day/year, respectively. The heritability and repeatability for 305 days milk yield and lactation length were 0.10, 0.11 and 0.27, 0.17, respectively.