We studied the effect of the antimicrobial drug «Multiomycin 1 %» on the hematological and biochemical pa-rameters of blood, the activity of digestive enzymes (amylase, alkaline phosphatase, protease), the structure of the mi-crobiocenosis of the small and large intestines, and the quality of the products. Based on the results of preclinical stud-ies, a production test was carried out in conjunction with the veterinary drug «Yuberin oral», as well as an assessment of the impact on the productivity of poultry was given. «Multiomycin 1 %» did not adversely affect the chickens. The drug had a positive effect on the activity of the digestive processes, increased their activity. Contributed to a decrease in the total microbial contamination in the contents of the small and large intestines and an increase in the content of bifidobacteria and lactobacilli. Combined use with yuberin contributed to an increase in safety, an increase in the aver-age daily gain, as well as a decrease in the incidence of gastroenteritis. The weight gain at the end of the experiment in the chickens of the experimental group was 3,74 % higher than in the control. The use of the veterinary drug «Multiomycin 1 %» did not have a negative effect on the quality of the products.