The article presents the results of studying the effect of feed additives «HitAcid» and «Veleguard BG» on the histological parameters of the muscles of broiler chickens of the Ross-308 cross. The study was conducted at the Department of Parasitology and Veterinary and Sanitary Expertise of the Federal State Budgetary Educational Institution of Higher Education «Moscow State Academy of Veterinary Medicine and Biotechnology – MVA named after K. I. Skryabin». During the study, it was found that the use of additives «HitAcid» and «Veleguard BG» stimulate the set of live weight of broiler chickens, and show an increase in the set of muscle mass of carcasses. Indicators of the thickness of muscle fibers and bundles of muscle fibers of the quadriceps femoris and superficial pectoral muscle of broiler chickens of the experimental groups exceed those of the control group. In a comparative assessment of the micromorphometric parameters of the studied muscles, the greatest thickness of muscle fibers and bundles of muscle fibers was noted in the experimental group «HitAcid». The data obtained indicate the expediency of using food additives based on organic acids in the diet of broiler chickens.