EN
The aim of the investigations was to evaluate the state of health of the udder on the basis of ATP in milk. The investigations were carried out on milk from the quarters of 67 cows reacting positively in Californian Mastitis Test. The level of ATP and the content of somatic cells were examined in milk samples from the morning milking. The level of ATP was determied liminometrieally by Olsson’s method using lucypheryn-lucypherase reagent, while Press- cott-Breed’s method was introduced to estimate the content of somatic cells. The correletion coefficients between the level of ATP and the contents of somatic cells depending on the intensity of udder inflammation. In quarter milk of udders with subclinical inflammation was noted a considerable increase of the ATP level- on the average from 1.50 to 164.7 mM/L, and the content of somatic cells increased from 150 000 to 2 000 000 cells cm"'. Mastitis considerably increases the level of ATP in milk. Deters mination of the ATP level in milk is a very susceptible diagnostic test of subclinical mastitis.