The aim of this study *was to investigate some 'biochemical and microbiological values for the early diagnosis of subclinical mastitis in healthy and mastitic cows.

In the present study, a total of .30 Brown-Swiss cows, in >5-7 years old, supplied by Konya Animal Research Centre, were used as materials.

Blood samples were taken from the animals at the same time as the milk. All the biochemical and microbiological determinations were performed on the same day. ALP, albumin, Na and K values Were determined in the blood serum samples. The counting of the PMN, LDH, ALP, Na and K values were measured in the milk samples.

In the subclinical mastitic cows, milk LDH, ALP, Na ve K values were found statistically significant. Furthermore, the counting of the PMN increased significantly. Blood serum sample values were not found s Latistically significant.

As a result, it was useful to determine of the LDH, ALP, Na, K and the counting of the PMN in milk for the early diagnosis subclinic mastitis. Other tests, blood serum albumin, Na and K values were not found mainly important for the early diagnosis of the subclinic mastitis.