Dual use of breeding stallions

Dual use of breeding stallions is possible without affecting the sperm quality
Reprod Domest Anim. 2023 Mar 7.
Authors
Britta Hensel # 1 , Ulrike Jakop # 1 , Marion Schmicke 2 , Filip Schröter 3 4 , Markus Jung 1 , Martin Schulze 1
Affiliations

1 Institute for Reproduction of Farm Animals Schönow, Bernau, Germany.
2 Department of Veterinary Endocrinology and Laboratory Diagnostics, University of Veterinary Medicine Hannover, Hannover, Germany.
3 Department of Cardiovascular Surgery, Heart Center Brandenburg, Brandenburg Medical School, Bernau, Germany.
4 Faculty of Health Sciences Brandenburg, Brandenburg Medical School Theodor Fontane, Potsdam University, Neuruppin, Germany.
# Contributed equally.

Abstract

Artificial insemination (AI) is commonly used in the equine industry to enhance the genetic value in breeding programs and to effectively utilize ejaculates. Many stallions are used as breeding stallions as well as in high-level sports competitions to improve their market value. The goal of the present study was to investigate whether this dual use of stallions influences the animals´ stress levels and/or the quality of their ejaculates. For this purpose, 18 stallions were grouped into two categories: breeding stallions with (BSC = breeding stallion competition), and breeding stallions without secondary use in competitions (BS = breeding stallion). Two ejaculates were collected at a one-week interval and analyzed with an extended spectrum of spermatological methods. Furthermore, saliva, as well as seminal plasma samples were taken, and the concentration of cortisol therein was determined. Additionally, dehydroepiandrosterone (DHEA) and the cortisol/DHEA ratio were analyzed and calculated for seminal plasma. After statistical analysis of the correlations and interdependences between the two groups, the results showed that the BSC group had significantly higher saliva cortisol levels (P=0.027) and tendentially higher DHEA concentrations in their seminal plasma (P=0.056). No difference between BS and BSC could be found in regard to the sperm quality parameters and the cortisol concentration in seminal plasma samples. It can be concluded that while active participation in competitions represents a stress factor, the dual use of stallions in breeding programs and sports competitions is possible without negative effects on their sperm quality.

Keywords: cortisol; semen preservation; show horse; sperm quality; stallion semen; stress.