Study of metabolic processes in cows with hyperbilirubinemia in the postpartum period

Abstract

Highly productive dairy farming requires strict adherence to the technology of feeding and keeping cows and competent herd management. Cows with liver pathologies during the transit period are tough to treat. We conducted studies of cows' health status after calving to identify biochemical signs of liver pathology and associated metabolic disorders. The survey of highly productive cows was carried out on four farms in the Leningrad region of the Russian Federation. Cows received different rations, differing in composition and nutritional value. A total of 108 animals were examined. Blood was taken from cows 10‐20 days after calving and examined in a biochemical laboratory for the content of metabolites, enzymes, hormones. The results of the study showed significant differences in the biochemical profile of cows in different farms. The incidence of hyperbilirubinemia in cows ranged from 12.5 to 45.8%. The severity of metabolic disorders was assessed depending on the degree of hyperbilirubinemia. It was found that the minor metabolic effects were observed in cows with bilirubin levels from 7 to 10 μmol / L (n = 11), which was accompanied by a slight increase in the concentration of β‐hydroxybutyrate (1.36 ± 0.12 mmol / L), as well as an increase in activity creatine phosphokinase (CK‐NAC) up to 319.3 ± 27.7 IU / L and lactate dehydrogenase (LDH) up to 1193.9 ± 31.5 IU / L. The concentration of glucose and cholesterol was in the reference range. In cows of this group, the concentration of cortisol and thyroxine was within the reference limits (76.5 ± 2.5 and 50.3 ± 2.7 nmol / l, respectively). In the study of cows with a moderate degree of hyperbilirubinemia from 10.0 to 16.0 μmol / L (n = 9), a predisposition to a decrease in glucose levels to 2.03 ± 0.12 mmol / L was noted against the background of an increased content of β‐hydroxybutyrate 1.84 ± 0.13 mmol / L, the level of cholesterol in cows was 2.43 ± 0.21 mmol / L. The activity of LDH and CK‐NAC was 1310.8 ± 69.3 and 401.5 ± 41.9 IU / L, respectively. A decrease in thyroxine concentration was found in 33.3% of animals, an increase in cortisol concentration ‐ in 55.5% (mean group values ‐ 48.4 ± 3.4 and 78.8 ± 6.5 nmol / l). In cows with the highest degree of hyperbilirubinemia from 17.0 to 39.0 μmol / l (n = 8), the most severe metabolic consequences were revealed, which practically did not give hope for the restoration of body functions. All cows showed an increase in β‐hydroxybutyrate to 2.79 ± 0.39 mmol / L, a decrease in cholesterol concentration to 1.8 ± 0.06 mol / L in the absence of hypoglycemia. In cows, the activity of CPK (1140.7 ± 222.7 IU / L) and LDH (2150.1 ± 94.4 IU / L) are significantly increased. The concentration of thyroxine in the studied cows was 22.03 ± 2.0 nmol / l. All cows in this group showed hypercortisolemia (140.2 ± 11.4 nmol / l). The studies made it possible to identify the relationship between the degree of liver damage and dysregulation of almost all types of metabolism.