The target of the research was to analyze the effect of antidiarrheal feed additives on calves average daily weight gain. In the study, 120 calves were analyzed. Newborns were selected into 3 treatment groups, control (without supplementation) and group with Ascophyllum nodosum (prebiotics), and mixture of Lactobacillus sporogenes, Enterococcus faecalis and Bifidobacterium bifidum (probiotics). Individual body weight of animal were determined after 2 hours post-partum. Monitoring of the growth intensity, as well as health status were done till 56 days of age. Significant effects (P