Funding for this research was provided by:
Javna Agencija za Raziskovalno Dejavnost RS (J3-6801, J3-9436, P4-0053)
Received: 18 May 2020
Accepted: 19 November 2020
First Online: 25 November 2020
Ethics approval and consent to participate
: This was retrospective study using data obtained during regular procedures with bulls in semen collecting centre, so no animal experiments were performed for the purpose of this study.
: Not applicable.
: The authors declare that they have no competing interests.