The aim of this experiment was to quantify the spread of Salmonella Typhimurium in weaned piglets by calculating R0 values. In addition, the effect of 2 feed additives, AROMABIOTIC“ and Shiitake mushroom, on the spread of Salmonella Typhimurium was evaluated. Fifty-nine piglets were allocated to 4 groups: AROMABIOTIC“ (A, n=16), Shiitake mushroom (B, n=16), positive (C, n=16) and negative controls (D, n=11). Half of the piglets of group A, B and C were experimentally inoculated with Salmonella Typhimurium, other piglets were used as susceptibles. Based on Salmonella isolation in faecal swabs, R0 values (95% C.I.) were 4.26 (1.40-34.69), 1.83 (0.86-9.38) and 4.29 (1.09-13.71) for group A, B and C, respectively. None of the measured parameters did indicate significant differences between the groups. Mortality rate was high in all 4 groups, what makes it necessary to repeat the experiment.