It is important to take care of calves and their health for good results in beef-raising. The aim of the work was to evaluate the effect of dietary supplements Lactovita and Biopolym on the frequency of diarrhoea occurrence in calves in the first stages of the period after weaning for milk nutrition. The experiment was conducted in farmers' cooperation Staré Hobzí, where Holstein Cattle are bred. Two groups of calves were made {--} control and experimental group. In an experimental group dietary supplements to support active immunity were served according to the guideline. In case of diarrhoea occurrence the calves from experimental group were cured in the same way as the calves from control group. The occurrence of disorders during the period of experiment, method and length of treatment were recorded. Recorded data were summarised and statistically evaluated. The calves were examined from 29th February to 20th December. The results proved positive effect of dietary supplements Lactovita and Biopolym, but these results were statistifically insignificant. It is assumed that in case of studying bigger groups the proof of statistical significance will be more probable