[Lactoperoxidase activity and thiocyanate content of milk from cows with mastitis in different lactation stages].

During three lactational periods (start, middle and end of lactation) of 35 milk cows suffering from mastitis and compared with 34 healthy milk cows of comparable milk production the activity of lactoperoxidase (LPO) and the SCN-content of the milk in each udder quarter were determined. Both components showed no alterations in the subclinical form of the disease. There exists a decrease of the LPO activity in the secretion of ill udder quarters, which will be distinct only in the individual animal and a strong increase of the SCN-content, which is also significant in comparison with the milk of healthy cows.