The aim of this study was to analyze the effects and significance of DGAT1 K232A polymorphism on milk production traits -milk yield, content of protein, fat and fat-to-protein ratio in milk during the first six months of lactation, with respect to the course of the body condition. The influence of year, calving season and month of lactation on these traits was also assessed. The investigation was conducted on 246 primiparous Holstein cows, calved from 2009 to 2011. DGAT1 genotypes were identified using the polymerase chain reaction -the restriction fragment length polymorphism technique (PCR-RFLP). The A and K allele frequencies were 0.73 and 0.27. Homozygotes KK were characterized by significantly (P