The results of breeding measures within the population of charolais cattlein the Czech Republic in 1991-1997

Data on the place and time of birth, the type of mating, sex of calf, the d am's body conformation, parity at the birth of calf, and live weights at bi rth, at the age of 120, 210 and 365 days of a set of 3 903 of Charolais cal ves in the Czech Republic were included in the observation. Data obtained f rom the central records were processed using the desk processor EXCEL '95, the statistical programme SAS / STAT 6.12 and the model equation comprising birth weight of calves, and body weights at 120, 210 and 365 days of age i n relation to the follows factors: year of birth of calf, month of birth of calf, region where the calf was born, the type of mating (AI or natural), sex of calf, the dam's body conformation, parity at the calf birth, birth w eight of calf when evaluating body weight of calf at 120, 210 and 365 days of age, body weight of calf at 120 days of age when evaluating body weight of calf at 210 and 365 days of age, and body weight of calf at 210 days of age when evaluating body weight of calf at 365 days of age. Birth weight of calves born in the consecutive years decreased significantly from year to year (P < 0.001). At 365 days of age the significance of difference in body weight was P < 0.05. The effect of the season of the year on birth weight of calves born was significant (P < 0.05). The highest birth weight was fou nd for calves born in winter and the lowest for calves born in autumn. Calv es born in winter attained significantly highest body weights up to 365 day s of age (P < 0.05). Differences in birth weights of calves born in 7 regio ns of the Czech Republic were significant (P < 0.001). Significantly highes t body weights of calves at 365 days of age (P < 0.001) were recorded in th e region where the highest birth weights were recorded. Significantly highe r (P < 0.001) birth weights of bull calves were obtained compared with heif er calves. Similarly, significant differences were found in body weights of bull calves and heifer calves at 365 days of age. A significant relationsh ip (P < 0.05) was found between birth weight of stillborn calves and diffic ult calvings. The dam's body conformation had a significant effect on body weight of calves at 365 days of age. Parity at the birth of calf had a sign ificant effect (P < 0,001) on birth weight and body weight at 365 days of a ge. The dynamics of a higher growth rate identified at birth of calves were retained up to the ages of 120, 210 and 365 days, and were significant (P < 0.001).