[Viscosity, pH and the protective properties of the diluents of bull seminal fluid after cryoconservation].

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.