Lipidemia and lipid contents in the liver in Holstein cows during transition period

The aim of the present study was to determine a correlation between blood concentration of lipids and the content of lipids in the liver of dairy cows in the transitional period. The Holstein dairy cows (n = 40) were divided into four groups: the first group (A) included late pregnant cows (n = 10) from the 10th to 4th day before calving; the second group (B) included late pregnant cows (n = 10) from the 4th to 1st day before calving; the third group (C) included clinically puerperal healthy cows (n = 10), whereas the fourth group (D) included puerperal ketotic cows (n = 10). The liver and blood samples were taken from all the cows. Pathohistological examination of liver samples showed statistically significantly higher (p < 0.01) lipid infiltration in ketotic cows compared to healthy cows in late pregnancy and puerperium. Biochemical examination of blood serum showed significantly higher values (p < 0.01) of nonesterified fatty acids (NEFA) and beta-hydroxybutyrate (BHB) in ketotic cows, such as lower blood concentrations of glucose (p < 0.01), triacylglycerols (TG) (p < 0.01), and total cholesterol TChol. (p > 0.05) compared to the values obtained in the blood serum in the groups of healthy cows before and after calving. The significantly positive correlations were determined between the content of lipids in the liver and blood concentration of NEFA (r = 0.67; p < 0.05) and BHB (r = 0.55; p < 0.05) as well as the negative ones between the content of lipids in the liver and blood concentrations of glucose (r = -0.45; p < 0.05), TG (r = -0.55; p < 0.05) and TChlol. (r = 0.39; p < 0.05). Our investigations suggested that changes in the blood concentrations of NEFA, BHB, TG, TChol. and glucose served as major biochemical indicators in determining ketosis and liver steatosis in the dairy cows in the transitional period.