the aim of our study was to evaluate influence of probiotic agents (Lactovita) and seaweed extracts (Biopolym) with antidiarrheal effects on the prevention of diarrhoea in calves. In the experiment 22 experimental and 22 control calves were observed. The results of the observed incidence of diarrhoea in the control and experimental groups showed a positive effect of probiotic Lactovita and seaweed extracts Biopolymer. 32% of calves in the experimental group and 45% of calves in the control group became sick. Unfortunately, we could not demonstrate the statistical significance of these differences. The weight gains found in the 4th week after birth were by 37.6% higher in the group with Lactovita and Biopolym than in the control group.