[Comparative studies of diagnostically significant enzymes in plasma, udder lymph and milk of healthy cows and cows with udder diseases].

Different secretions (colostrum, milk, dry udder secretion) of every quarter, peripheral lymph from superficial lymph vessels of the mammary gland and blood from the V. epigastrica superficialis were obtained in 43 cows at different stages of lactation. In these samples the activity of 5 enzymes (LDH, NAG, AP, LAP, GGT) was determined. Levels of LDH and NAG were highest in blood plasma and udder lymph. Levels of LAP, AP and GGT were highest in milk increasing in this order. LDH, NAG, AP and LAP were correlated in both compartments. Changes of the functional state (dry or colostral period) and tissue disturbances of the mammary gland were accompanied by marked changes of enzyme activity in the secretions, but were without obvious influence on enzyme levels in blood plasma and udder lymph.