INVESTIGATIONS ON BLOOD ENZYME ACTIVITIES IN COWS WITH SUBCLINICAL AND CLINICAL KETOSIS.

Ketosis is a common metabolic disease in high-yielding dairy cows incurring substantial economic losses to cattle husbandry. The present study was performed on 157 Holstein cows with yearly milk yield of 9000–11000 L, in their 1st to 4th lactation and average body weight 450–550 kg. The animals were divided into 3 groups: first group – pregnant cows (from day 15 to day 0 pre-calving); second group – recently calved (from day 0 to day 15 postpartum) and third group – lactating (from day 30 to 45 postpartum). Blood concentrations of ?-hydroxybutyric acid (????) were assayed in all cows and on the basis of results, they were classifies as healthy (control, C), affected with subclinical ketosis (SCK) and clinical ketosis (CK). Blood enzyme activities of Aspartate aminotransferase (ASAT, U/l), Alanine aminotransferase (ALAT, U/l), Lactate dehydrogenase (LDH, U/l), Creatine kinase (CK, U/l), ?-glutamyltransferase (GGT, U/l) and Alkaline phosphatase (A?, U/l) were determined. The results indicated that pregnant cows from group I were affected with subclinical, not clinical ketosis (???? <2.6 mmol/l). After calving and in the period of lactation (groups II and III), cows suffered from both forms of ketosis. Blood biochemical analysis of activities of ASAT, ALAT, LDH, ?P, CK and GGT demonstrated a various extent of statistically significant hyperenzymemia in SCK and CK, corresponding to the severity of cell damage of parenchymal organs.