BIOCHEMICAL MARKERS OF HEPATOBILIARY SYSTEM DYSFUNCTION IN FRESHLY CALVED COWS

The purpose of research is to study the biochemical parameters of the blood of cows to search for informative biomarkers for assessing hepatobiliary disorders in the early lactation period. Objectives: a comprehensive biochemical study of the blood of cows in the early lactation period and determination of the activity of liver and skeletal muscle enzymes as indicators characterizing liver cell damage. Experimental studies were carried out in 7 farms of the Altai Region. A total of 87 blood samples were collected from animals during the study period. The material for research was the blood serum of cows during the period up to 45 days of lactation. As a result of research, it was found that in cows with fatty liver degeneration there is a significant increase in the concentration of bilirubin in the blood - up to 13.72 µmol/l, a decrease in the concentration of albumin beyond the standard ranges to 26.4 g/l cholesterol to 1.74 mmol/l, compared to healthy animals. The level of triglycerides in the blood of sick cows decreases to 0.33 mmol/l, compared to healthy animals (0.47 mmol/l), however, these changes are within standard intervals (0.22–0.55 mmol/l). A study of circulating liver enzymes showed that in cows with fatty degeneration there is a significant increase in the enzymatic activity of aspartate aminotransferase (AST) to 148.3 U/l, glutamyltransferase (GGT) to 30.0 U/l and creatine kinase (CK) to 667.8 U /l, which is 1.95, 1.55 and 6.71 times more than in healthy animals, respectively. Thus, changes in the concentrations of bilirubin, cholesterol, albumin, AST and GGT can be used as a diagnostic algorithm that is highly informative when testing disorders of the functional state of the liver, which will allow for timely correction.