[Survivability and penetration capacity of bull spermatozoa frozen by 3 technics].

Studied was the survival and penetration capacity of bull spermatozoa frozen after the following technologies--pellet, straw, and minitube--and the results obtained were compared via biologic experiments. The minitube technology of freezing the semen led to higher thermal resistance of the spermatozoa as against freezing in the form of straws and pallets (363.5 +/- 8.

[Cryobiological characteristics of bull sperm].

Investigations were carried out on the concentration of live spermatozoa and their viability in various layers of the pellets of frozen bull semen. Studied were also the 'nests' of dry snow for the presence of organisms and spermatozoa and the likeliness of their transmitting into the pellets of frozen semen. It was found that the concentration of live spermatozoa and their viability were highest in the central part (core) of the pellets, and lowest--in the peripheral layers.

[Thawing of bovine seminal fluid].

Comparative experiments were carried out at 39 degrees C and at 70 degrees C in water bath for the thawing of seminal fluid frozen in straws. The motility of spermatozoa was followed up as well as the absolute survival rate after thawing. By means of a thermocuple the temperature rise was traced as occurring in independence on the weather.