Possibilities for Improving Sperm Quality of Young Bulls under Cryopreservation by Se Supplement

1 Institute of Biology and Immunology of Reproduction, BG-1113 Sofia, Bulgaria
2 University of Shumen “Ep. K. Preslavski”, BG-9700 Shumen, Bulgaria


VAISBERG, Ch., M. BOYCHEF and K. MITEVA, 2002. Possibilities for improving sperm quality of young bulls under cryopreservation by Se supplement. Bulg. J. Agric. Sci., 8: 317–321

The aim of study is testing possibilities for improving sperm quality of young bulls under cryopreservation by means of addition of 160 μg Se/kg of dry matter (DM) to the basic ration containing 70 μg Se/kg DM.
Using a photokinezigraphic method, the motility of thawed spermatozoa were characterized and individual particularities in the sperm quality of the investigated bulls after cryopreservation were established.
A concentration of 70 μg Se/kg DM is suitable regarding to the resistance of spermatozoa under the cryopreservation of ejaculates of some bulls while for others is in dificit. The additional Se to the feed with a view to the increasing of concentration upto 230 μg Se/kg DM in the experimental group improve the quality of frozen sperm, but in the control group in which there is not change of Se concentration, the quality of the ejaculates in the time of testing becomes worse, which is probably due to the high summer temperatures.
The experiment show, that increasing of the Se level in diet of young bulls from 70 to 230 μg Se/kg DM has a positive effect on the quantitative indexes of bulls with low quality frozen semen. It's seem that under summer hot condition, increasing level of Se from 70 to 230 μg/kg ration DM have favorable effect on sperm resistance. In other words unfavorable effect of high temperature could at least partly be overcome by optimization of Se level in the ration of bulls.

Key words: bull, spermatozoa, photokinezigraphia, motility, selenium, temperature