[Trypsin inhibitor activity in the colostrum of cows].

The activity of the colostral trypsin inhibitor (CTI) was studied in seven milkings of colostrum in the course of the first five days after calving in 15 cows. The activity of the total trypsin inhibitor in the colostrum was ascertained in the course of the first two days after calving in ten cows in their second to fourth lactations and also in the colostrum of the first milking after calving in the case of 11 cows. The greatest CTI activity was found in the colostrum of the first milking after calving (301 micrograms X ml-1). Between the CTI activity and the concentration of total protein (CB) in the whey of the colostrum from the first and second day after calving there was found to be a statistically significant correlation (r = +0.929). The activity of total trypsin inhibitor was also highest in the colostrum from the first milking (499 micrograms X ml-1). After calving the CTI and the total trypsin inhibitor activities in the colostrum gradually dropped. Between the activity of the total trypsin inhibitor and the CB concentration in whey from the first, third, fifth and seventh milkings after birth a statistically significant correlation was found (r = +0.972). Statistically significant correlations were also found between the activity of the total trypsin inhibitor, the specific gravity of colostrum, the concentration of total protein and gamma-globulins in the whey of the colostrum from the first milking after calving. In metabolic alkalosis the concentration of total protein in the whey and the activity of trypsin inhibitor were found to be considerably lower than the average values.