[Evaluation of semen quality after freezing at the temperature of liquid nitrogen using a modification of two different methods].

Spermatozoon survival rate was analysed after freezing at the temperature of liquid nitrogen (-196 degrees C) with the application of three different cryoprotector substances, vitelline and non-vitelline. A modified method, based on the use of sperm cells of small diameter, was introduced in freezing semen. The best results were achieved while using non-vitelline, multi-ionic cryoprotector.