ASSESSMENT OF THE METABOLIC STATE OF METABOLISM IN HOLSTEIN COWS USING MILK BIOMARKERS

The aim of research is to study the levels of urea, molar concentration of beta-hydroxybutyrate and traces of acetone in the milk of Holstein cows of different populations and their relationship as biomarkers of the occurrence of possible forms of ketosis. The distribution of biomarkers of the picture of ketosis occurrence was studied by determining beta-hydroxybutyrate and traces of acetone in the milk of Holstein cows of different populations. The components of the cows' milk were determined using the CombiFoss 7 DC analyzer. More than half of the herd of cows in the Moscow Region (52.9 %) were healthy animals. During the experiment, about 43 % of cows were found with a subclinical form of ketosis, while 4.6 % of 11,529 heads had a clinical form. Negative values of the molar concentration of BHB and acetone were also found, indicating their absence in milk. In 95 % of cases, animals from the Ladozhsky dairy farm did not show any signs of ketosis. Subclinical ketosis with high values relative to the norm of acetone traces and molar concentrations of beta-hydroxybutyrate was predicted for some cows in the herd of the Ladozhsky dairy farm. In isolated cases, the clinical form of ketosis of animals in the herd of the Ladozhsky dairy farm was manifested from calving to the peak of lactation. A significant decrease in daily milk yield in cows by 8.7 kg of milk was noted with increased values of fat percentage and urea. Acetone values are 1.9 times higher than the threshold value of 0.30 mmol/l and beta-hydroxybutyrate 1.4 times higher than the threshold value of 0.15 mmol/l in animals with ketosis. In the milk of animals with ketosis, fatty acids – palmitic, stearic, oleic, long-chain, monounsaturated, saturated and trans isomers significantly and highly significantly exceed the values of healthy cows with normally functioning metabolism and physiological state. Monthly monitoring of individual milk samples with determination of metabolic biomarker values is important in assessing the metabolic state of cows.