| Abstract: | Possibilities of the diagnostic utilization of determined thermostable portion of the ALP activity in bovine serum were studied. The work is based on the finding that the total ALP activity is formed by two fractions with different sensitivity to the temperature of 56 degrees C. Dynamics of the loss of ALP activity during serum heating was of an equal character in all four tested groups. The loss was always highest during the first minutes of heating, after 15 to 20 minutes it became equal. A period of 15 minutes of the serum heating is sufficient for obtaining information on the size of the ALP thermostable fraction. The ALP activity and its residue after 15-minute thermal inhibition (thermostable portion) were tested in the sera of 163 head of cattle divided into seven groups. The size of this residue was related to the age of animals, degree of gravidity did not affect the residue. The thermostable portion in 6 to 10 months old bullocks was 14.86 +/- 4.93%, in 2.5 to 5 years old heifers 41.20 +/- 20.37% and in clinically healthy dairy cows 54.35 +/- 18.26%. In a group of calved breeding cows 44.13 +/- 19.74% of the initial activity remained. Determination of the thermostable ALP fraction can be applied with certain limitation in pre-clinical diagnostics of disorders of mineral metabolism in bones of cattle. In herds of healthy dairy cows the value of thermostable portion should not be lower than 45% of the original ALP activity. In 2.5 to 3 years old heifers this level is considered to be 35%. |
