[Enzyme activity of the seminal fluid of bulls after deep freezing and incubation at 39 degrees C].

The study of bull semen revealed that the activity of alkaline phosphatase in the semen plasma and spermatozoa did not change, however, upon incubation at 39 degrees C for at least 5 hours the activity of the enzyme dropped nearly 10 times. The activity of GOT in both plasma and spermatozoa rose after deep freezing, but the difference recorded were statistically insignificant. Upon incubation of semen at 39 degrees C in the course of five hours the activity of this enzyme decreased, although insignificantly. The differences were likewise insignificant with the drop of GPT following deep freezing. It was concluded that the changes with all three enzymes cannot be used as reliable markers of the injury of spermatozoa following deep freezing.