[Thiocyanate content in blood plasma, udder lymph and milk from healthy cows and cows with mastitis]

After storage for more than one year the SCN(-)-content of udder lymph was not changed seriously, but in blood serum and mainly in milk, there is an evident decrease. In lactational cows with healthy udders the SCN(-)-content of blood plasma is higher than in milk (in average twice). There is no difference of the SCN(-)-content of the four udder parts of healthy cows. Decrease of milk production (10. to 13. lactational month) causes an increase of the SCN(-)-content of the milk, it is not changed in subclinical mastitis. In lactational cows with healthy udders the SCN(-)-content of udder lymph is nearly triple higher in average than in milk of the corresponding quarter of the udder. The existence of a common compartment of SCN- in blood and udder lymph is assumed, which is separated from them of the milk by the blood udder barrier.