Influence of lipolysis and ketogenesis to metabolic and hematological parameters in dairy cows during periparturient period

The aim of this study was to examine the characteristics of the metabolic profile and complete blood count in cows in the periparturient period on the basis of the intensity of lipolysis and ketogenesis (concentration of non esterified fatty acid – NEFA and betahydroxybutyrate – BHB). Based on median values of NEFA and BHB cows were divided into 3 groups: cows physiologically burdened with catabolism (NEFA and BHB levels above the median one week after parturition), cows significantly burdened with catabolism (NEFA and BHB levels above the median one week before and after parturition) and cows that are not burdened with catabolism (NEFA and BHB below the median, i.e. the control group). The median value of NEFA was 0.27 mmol/L one week before parturition and 0.61 mmol/L one week after it. The median value of BHB was 0.51 mmol/L one week before parturition and 0.99 mmol/L one week after it. A significant group effect was shown for each week separately, so that cows physiologically burdened with catabolism and/or cows significantly burdened with catabolism compared to the control group have the following features of the metabolic profile and complete blood count: higher concentrations of NEFA and BHB (weeks: -1, 1, 2, 4, 8), lower concentrations of glucose (weeks: 1, 4), lower concentration of cholesterol (week 8), lower concentrations of total protein (weeks: 1, 2), lower concentrations of urea (weeks: 1, 2, 4, 8) and a higher concentration of bilirubin (weeks: - 1, 1, 2, 4, 8), increased levels of AST (weeks: -1, 1) and ALT (weeks: -1, 2), lower value of Ca (week -1), lower hemoglobin concentration (week -1), lower white blood cell count (week 4), a larger number of neutrophils (weeks: -1, 1, 2) and a higher number of lymphocytes (week 4). Using the method of factor analysis and principal components showed that NEFA, BHB and glucose are the major components that affect the metabolic profile and blood count, making 71.8% of the variability of all parameters. Cows with hypoglycemia, hypocalcemia, hypoalbuminemia, hyperbilirubinemia, decreased hemoglobin concentration and/or red blood cell count and neutrophil to lymphocyte ratio greater than 1 showed significantly higher concentrations of NEFA and BHB compared to cows with parameters within normal ranges. Complete ROC (receiver operating characteristics) analysis showed that NEFA and BHB are important diagnostic indicators that allow the separation of cows with parameters out of the reference values from cows with normal values of parameters in the metabolic profile and blood count (0.5 less than AUC less than 0.87). Reliability of identification of cows with parameters that are out of the reference value increases with increasing concentrations of NEFA and BHB, which confirms that intense lipolysis and ketogenesis start a series of compensatory processes in the metabolism in cows. The results confirm that NEFA and BHB significantly affect the value of numerous metabolic and hematological parameters in the periparturient period.