Relevance. It is known that genotypic features affect the activity of the functioning of regulatory systems, which is accompanied by changes in the intensity and direction of digestive and metabolic processes. The digestibility and use of nutrients, as well as the need for them in animals of different origins are not the same. Therefore, the study of the species composition and enzymatic properties of microorganisms in hybrid animals is of great interest. Scientific research in this area can expand the species diversity of cellulolytic microorganisms through the use of wild forms of sheep, in which the process of splitting and digesting raw fiber occurs more intensively.Methods. The species composition of the microflora and the main groups of microorganisms (total microbial number (OMH), lactic acid, enterococci, yeast-like fungi and cellulolytic microorganisms) were determined in the microbiology laboratory of the L.K. Ernst FITZ VIZH in 2021–2023 by seeding tenfold dilutions into accumulative and differential diagnostic media, followed by counting their number (CFU/ml) by groups of microorganisms.Results. According to the results of the study of the species composition of the scar content of hybrid sheep of different bloodlines, the largest number of microorganisms in the main groups was observed in hybrids — sheep 1/4 Argali × 3/4 Romanovskaya. The largest number of cellulolytic microorganisms with high enzymatic activity was isolated from four-breed hybrids: 1/32 Argali × 7/32 Romanovskaya × 8/32 Mouflon × 16/32 Katadin.