The purpose of the experiment was to estimate the possibility of substitution of antibiotic for dried brewery’s yeast (Saccharomyces cerevisicae). The 540 weaners were chosen to experiment then divided into three experimental groups. The animals were fed with the same mixture differing with kind of used additive. First group (control) fed mixture supplemented with antibiotic (20 ppm of avilamycin). The animals from groups 2nd and 3rd fed mixture with 1 or 2.5% of dried yeast. The experiment was carried at the period from 45 day of life to day in which animals reached 30 kg of body weight. The rate of growth, feed intake and health condition of the animals were controlled. The weaners from group 3rd (2.5% of yeast) had similar rate of growth as animals from control group (20 ppm of avilamycin). The higher concentration of protein and albumin in serum and lower level of urea were due to the better feed utilization especially protein in the groups 2nd (1% of yeast) and 3rd (2.5% of yeast). Application of higher dried brewery’s yeast dosis caused that there the introductory signs of immunosuppresion – higher hemoglobin, erythrocytes and leucocytes concentrations were observed. The antibiotic in the mixture for weaners could be replaced dried brewery’s yeast at amounts 1-2% into the starter mixture with a good zoohigienical condition.

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