Acta Vet. Brno 2022, 91: 339-346

The effects of egg yolk-based and egg yolk-free diluents on the post-thaw quality of bull spermatozoa

Jan Vodička, Jan Pytlík, Martina Stádníková, Luděk Stádník, Jaromír Ducháček, Radim Codl, Zuzana Biniová

Czech University of Life Sciences Prague, Faculty of Agrobiology, Department of Animal Science, Prague, Czech Republic

Received April 12, 2022
Accepted October 10, 2022

The aim of this study was to evaluate the effects of 3 different commercially available extenders – AndroMed® (soy lecithin-based), Optidyl® (with the addition of ionized egg yolk), and BULLXcell® (with the addition of fresh egg yolk) – on bull spermatozoa quality, which was evaluated using the parameters of spermatozoa motility, viability, plasma membrane damage, acrosome damage, and mitochondrial activity after thawing and during a 2 h long thermoresistance test. The spermatozoa quality indicators were appraised by computer-assisted semen analysis and a flow cytometer. Significant differences (P < 0.01) between bulls were registered in all indicators measured. The highest average values of spermatozoa total motility and viability were achieved using BULLXcell® extender (44.33%; 52.06%). Variances in comparing this extender with Optidyl® and AndroMed® were −0.83%, −2.64%; −8.33%, −9.51%. The differences found between the egg yolk-based diluents (BULLXcell® and Optidyl®) and AndroMed® were significant (P < 0.01). Therefore, the more valuable extenders for bull semen dilution were egg yolk-based extenders, which provided higher post-thaw spermatozoa survival and quality than the soy lecithin-based extender.


This research was funded by the Ministry of Education, Youth and Sports of the Czech Republic (“S” grant), the Ministry of Agriculture of the Czech Republic (NAZV Project No. QK22010270) and the Czech University of Life Sciences Prague (SGS Project No. SV21-6-21320).


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