Biochemical parameters in 40 Holstein-Friesian cows have been studied. Cows were in the second and third lactation. Blood was sampled during four productive periods as follows: in the dry period (2-3 weeks before delivery), the postpartum period (0-2 weeks postpartum), in the middle of lactation (15-17 weeks postpartum) and late lactation (2-3 weeks before the start of drying). Concentrations of glucose, protein, cholesterol, bilirubin, urea, NEFA, BHB, ALT, AST, Ca, P and Mg were testes by using standard biochemical methods. The parameters of the metabolic profile of Holstein-Friesian cows correspond to the reference values in cattle. Parameters are within the normal (Gaussian) distribution. Periparturient changes in the concentrations of metabolites are characterized by negative energy balance, with the development of liver failure and reducing the concentration of calcium. Frequency distribution of values of metabolic profile suggests that clinically healthy animals during the entire period of lactation may show signs of metabolic changes, which is probably caused by high demand for milk production, due to load stress and inadequate nutrition.