Abstract
Aim
The physiological indexes of the copulatory behavior of the stallion have not been investigated in detail and may differ from those of other species, such as humans and rats.
Methods
In order to understand the breeding capability of various stallions, their behavior during copulation was observed, and heart rate (HR) and the plasma concentrations of norepinephrine (NA) and epinephrine (Ad) were measured sequentially for a total of 13 copulations carried out during 2 days.
Results
The mean HR at rest was 35.3 ±0.9 beats per minute (b.p.m.) and it peaked during mounting (162.1 ±5.4 b.p.m.). The HR at ejaculation was 145.7 ±5.1 b.p.m, which was less than the peak. The plasma concentrations of NA and Ad showed similar changes to the HR; immediately after ejaculation they were, respectively, 4.7-fold and 1.9-fold higher than the resting values and there was a difference in the degree of increase of each catecholamine.
Conclusions
The present results show that in the stallion the HR peaks at mounting and there is a greater change in the activity of the sympathetic nervous system because of the shortterm, highly intense exercise performed during copulation. It is considered that this, combined with the particular mental stress placed on the stallion during copulation, has the potential to cause sudden cardiac death.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Fraser AF. The Behaviour of the Horse. CAB International, Wallingford, 1992.
Arai Y. [Central nervous control of male reproduction]. Nippon Rinsho 2002; 60: 7–15. (in Japanese.)
Kihara K. [Mechanism of ejaculation]. Nippon Rinsho 2002; 60: 83–7. (in Japanese.)
Klug E, Deegen E, Lazarz B et al. Effect of adrenergic neurotransmitters upon the ejaculatory process in the stallion. J Reprod Fertil Suppl 1982; 32: 31–4.
Okauchi K, Miwa S, Katayama H. Heart rate during sexual excitation in domestic animals. Bull Fac Agric, Miyazaki University 1975; 22: 245–56. (in Japanese.)
Houpt KA. Domestic Animal Behavior for Veterinarians and Animal Scientists, 3rd edn. Iowa State University Press, Iowa, 1998.
Kurosawa M, Takeda F, Nagata S et al. Circadian variations in plasma adrenaline and noradrenaline in the Thoroughbred horse. J Equine Sci 1997; 8: 81–8.
Saito TR, Hokao R, Terada M et al. The telemetric monitoring of heart rate during copulatory behavior in the male rat. Scand J Laboratory Anim Sci 2001; 28: 108–113.
Littler WA, Honour AJ, Sleight P. Direct arterial pressure, heart rate and electrocardiogram during human coitus. J Reprod Fertil 1974; 40: 321–31.
Waring GH. Sexual behavior of stallions. In: Waring GH, ed. Horse Behavior, 1st edn. Noyes Publications, New Jersey, 1983; 106–119.
Kurosawa M, Nagata S, Takeda F et al Plasma catecholamine, adrenocorticotropin and cortisol responses to exercise of the Thoroughbred horse. J Equine Sci 1998; 9: 9–18.
Willam F. Ganong. Review of Medical Physiology, 5th edn. Lange Medical Publications, East Norwal, 1973.
Snow DH, Harris RC, MacDonald IA et al. Effects of high-intensity exercise on plasma catecholamines in the thoroughbred horse. Equine Vet J 1992; 24: 462–67.
Nagata S, Takeda F, Kurosawa M et al. Plasma adrenocorticotropin, cortisol and catecholamines response to various exercises. Equine Vet J Suppl 1999; 30: 570–74.
Author information
Authors and Affiliations
Corresponding author
About this article
Cite this article
Terada, M., Momozawa, Y., Komano, M. et al. Changes in the heart rate and plasma epinephrine and norepinephrine concentrations of the stallion during copulation. Reprod Med Biol 4, 143–147 (2005). https://doi.org/10.1111/j.1447-0578.2005.00093.x
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1111/j.1447-0578.2005.00093.x