Interrelationships between selected blood markers of renal functions and milk components tested in dairy cows

There are various methods for the assessment of internal metabolism and internal organ functions in the monitoring of highly productive dairy cows. The knowledge of various relationships, including significant correlations between different milk and blood parameters, based on the results of laboratory analyses is very important in veterinary diagnostics and useful in bovine practice. The aim of the present study was to analyze correlations between selected blood serum parameters included in the renal profile, such as concentrations of urea (U), creatinine (C), uric acid (UA), total protein (TP), albumin (A), sodium, and potassium, and the values of selected parameters of milk components, such as somatic cells count (SCC), bacteria colony forming units (CFU), milk fat (MF), milk protein (MP), lactose (ML), solids, solids non-fat (SNF), and milk yield (MY). Blood and milk samples were collected at the same time from 11 clinically healthy milking cows during the late lactation period. The animals were tested three times during 3 days at daily intervals, which yielded 33 sets of test results. This model of testing made it possible to obtain a highly homogeneous group of animals for testing and enabled us to determine statistical correlations between selected biochemical parameters of the renal blood profile and components of milk. Significant negative correlations were observed between U and MY, C and MY, UA and MY, as well as between C and TP. Significant positive correlations were observed between TP and SCC, TP and MP, TP and SNF, A and MP, A and SNF, sodium and SNF, as well as between TP and A. The results of blood and milk tests made it possible to precisely monitor the basic health status of cows in relation to selected blood parameters of the renal profile. The analysis of links between metabolic pathways in the relationship between blood and milk homeostasis in high-yielding dairy cows may have diagnostic significance in real cattle practice.