The search for potential biomarkers that signal the state of the physiological status of the organism of highly productive cows, which are taken into account in further selection aimed at increasing the quantity and quality of dairy products, is becoming relevant in many countries engaged in dairy cattle breeding. The study was conducted on the basis of the Ladozhsky breeding plant (Krasnodar Krai) — a branch of the L.K. Ernst Federal State Budgetary Institution. Studies of blood samples were carried out on an automatic biochemical and enzyme immunoassay analyzer «Chem Well». The analysis of the expanded component composition of milk was made on the analyzer «Combi Foss 7» (IFS). Based on the results of the studies, we calculated the relationship between the component composition of milk and blood of cows. For daily milk yield, moderate positive correlations were observed with phospholipids r = 0.364, cholesterol r = 0.324, albumin r = 0.316 and magnesium r = 0.309. Moderate relationship between cholesterol and lactose was r = 0.408 and between cholesterol and SOMO r = 0.307. Direct moderate relationship r = 0.376 between lactose and ALT, r = 0.361 — albumin, r = 0.455 — phospholipids. Moderate direct correlation between trans-isomers and alkaline phosphatase was r = 0.309, chlorine — r = 0.259. Moderate inverse correlations appeared in relation to daily milk yield — erythrocytes r = 0.312. Moderate inverse correlations between transisomers and cholesterol r = -0.385, urea r = -0.428. The relationships of other components of milk and blood, both direct and inverse, turned out to be weak and very weak.