[Cryoprotective properties of the components of diluents for bull seminal fluid]. / Krioprotektivni kachestva na niakoi sustavki na razrediteli za semenna technost ot bik.

Studied were the protective qualities of lipovitellinine with regard to spermatozoa at cryoconservation. It was found that following centrifugation at 2000 G of the GH22L diluent for 20 min the electrophoretic investigations on Cellogel revealed a strong drop of lipovitellinine from 25.33 +/- 4.21 to 2.33 +/- 0.24 per cent. With the Nagaze-Niva diluent the drop was from 24.20 +/- 4.56 to 14.10 +/- 2.95 per cent. The changes in the percent ratio of the protein fractions in dilution of bull semen at 1 + 4 were shown to be considerable with the GH22L diluent after the separation of part of the lipovitellinine. With the Nagaze-Niva diluent these changes were negligible. The separation of part of the lipovitellinine with GH22L led to an essential drop of spermatozoid motility and of the heat resistance of semen following thawing. With the Nagaze-Niva diluent the changes in the qualities of spermatozoa were not substantial after separating part of the lipovitellinine. It was also found that the GH22L diluent produced a better cryoprotective effect on spermatozoa than the Nagaze-Niva diluent.

[Viscosity, pH and the protective properties of the diluents of bull seminal fluid after cryoconservation]. / Prouchvaniia vurkhu viskoziteta, pH i protektivnite kachestva na razrediteli za semenna technost ot bik sled kriokonservatsiia.

The changes in the values of viscosity and pH of some diluents in centrifugation and heat treatment and their protective qualities on bull semen at cryoconservation were followed up. It was found that following centrifugation of the gamma X22 pi diluent at 2,000 G for 20 min viscosity considerably dropped (from 2.240 +/- 0.1170 to 1.234 +/- 0.1153 centipoises). With the Nagaze Niva diluent treated under the same conditions the drop of viscosity was not reliable (from 1.368 +/- 0.1063 to 1.258 +/- 0.147). Following thermal treatment at 70 degrees C for 60 min viscosity in the first case considerably rose (from 2.440 +/- 0.1170 to 2.839 +/- 0.1319 centipoises), while in the second case the difference was not reliable (from 1.368 +/- 0.1063 to 1.706 +/- 0.2579 centipoises). After centrifugation at 2,000 G for 20 min and thermal treatment at 70 degrees C for 60 min the values of the two diluents' pH did not change. The drop of viscosity following centrifugation of the gamma X22 pi diluent was found to be associated a with a drop of its protective qualities on the spermatozoa too; and vice versa--the rise of viscosity of the same diluent following thermal treatment increased its protective qualities with regard to spermatozoa following cryoconservation. The centrifugation of the Nagaze Niva diluent at 2,000 G for 20 min and its thermal treatment at 70 degrees C for 60 min did not lead to statistically reliable changes in its viscosity. Neither were statistically reliable the changes in its protection of spermatozoa after cryoconservation.