INVESTIGATION ON THE ENZYME PROFILE DURIN G THE PREPARATORY PHASE OF DELIVERY IN CATTLE

In order to evaluate possible changes in enzyme activities during the last 263 h of pregnancy, blood samples were collected in 24 h interval s from 9 heifers and 14 cows of the breed ''German Black Pied''. The a ctivities of aspartate aminotransferase (AST), glutamate dehydrogenase (GLDH), creatine kinase (CK) and gamma glutamyltransferase (GGT) in b lood serum were determined. Whereas during the last 10 days before par turition, a change in activity could not be detected for any of the en zymes studied, sub partu there was an increase in activity of AST and CK. There was no influence of calving on the activity of GLDH and GGT. Mean activity of AST increased bg 4.3 U/L to 32.9 U/L. Mean activity of CK rose to 60.3 U/L, which corresponded to a statistically signific ant average increase of 29.5 U/L. There was no diurnal influence on ac tivity of the respective enzymes. During the last 4 days ante partum, heifers had statistically significant higher activities of GLDH and CK than cows. After parturition, this difference was not statistically d ifferent. Immediately post partum, activities of AST (35.7 U/L) and CK (84.3 U/L) were statistically significantly higher in animals which c aIved with assistance than in cows with spontaneous delivery (AST: 31. 1 U/L, CK: 40.9 U/L).