Pig breeding, as an independent livestock sector in Russia, has been developing steadily since 2008. This was facilitated by the adoption of the agricultural development program, which assumed an increase in state support for the agro-industrial complex. However, the intensification of pork production places high demands on the quality of livestock, which necessitates the use of breeds, types and lines that can withstand the loads of modern industrial technology without reducing productivity. The article presents the morphological parameters of the peripheral blood of store pigs of large white breed, obtained using a hematology analyzer. Based on the analysis of the data obtained, the authors have came to the conclusion that there is a tendency to an increase in the number of erythrocytes and hemoglobin, and a decrease in the number of leukocytes and platelets with age in the blood of fattening pigs. These changes can be associated with high growing capacity of fattening piglets and the implementation of effective preventive measures on the farm in relation to piglet anemia.