EN
The aim of presented study was to estimate the influence of calving season, cow body weight, calf body weight at birth on body weights and daily gains of large calibre beef breeds calves, i.e. Charolaise and Simmental. Estimations were made of the effect on the body weight and daily body gain of calves of the following factors: cow genotype (purebred Charolaise or Simmental, 50% of Charolaise or Simmental genes), calving season (summer feeding: May-October, winter feeding: November-April), cow body weight (£550 kg, >550 kg), calf body weight at birth (£35 kg, >35 kg). The dam genotype had highly significant influence on calf body weight at birth. Pure-bred Charolaise cows delivered calves over 6 kg heavier than calves from Simmental ones. Mothers with 50% of Charolaise blood ratio delivered calves of higher by about 2 kg body weight than cows with 50% of Simmental blood share.