Hradecká E. author Čítek J. author Panicke L. author Řehout V. author Hanusová L. author text journal article 2008 : We analysed the relations of estimated breeding values (EBV) of 315 German Holstein sires to their genotypes in growth hormone gene (GH1), growth hormone receptor gene (GHR) and acylCoA-diacylglycerol acyltransferase 1 (DGAT1). The strong relation of DGAT1 K232A to the estimated breeding values for milk production traits has been confirmed, when allele DGAT1^K was connected with higher milk fat yield, milk fat and milk protein content, while allele DGAT1^A increased milk yield and milk protein yield. The effect of DGAT1 genotype explained from 4.70% of variability of EBVs for fat yield to 31.90% of variability of EBVs for fat content. The evaluation of GH1 127 Leu/Val and GHR 257 SNP polymorphisms did not reveal an association of their polymorphism with EBVs for milk production traits, except the EBVs of GHR^G/GHR^G homozygotes for fat yield, which were significantly lower. The effect of GH1 or GHR genotype explained only a negligible portion of variability of EBVs (R² < 1.00% in most cases). bovine; GH1; GHR; DGAT1; milk production; breeding value; Holstein 10.17221/362-CJAS https://cjas.agriculturejournals.cz/artkey/cjs-200806-0002.php https://cjas.agriculturejournals.cz/artkey/cjs-200806-0002.php continuing 53 6 238 246 2008 12121819 periodical academic journal