Seasonal changes in semen quality and freezability in the Warmblood stallion.
Abstract: The objective of this study was to investigate seasonal changes in stallion semen quality and to determine the best time for semen cryopreservation. Experiments were performed using 10 Warmblood stallions from the National Stud Farm in Avenches (Switzerland). Ejaculates were collected and frozen every other week during 1 year from January to December 1999. Volume, concentration, and motility, and the number of morphologically normal sperm and sperm with major defects (abnormal heads, acrosome defects, nuclear vacuoles, proximal droplets, abnormal midpieces) were evaluated. For all frozen-thawed semen samples motility as well as viability (SYBR-14/PI) was tested, and the hypoosmotic swelling test (HOS) was performed. To analyze seasonal differences 4 periods of 3 months each were defined: autumn (September, October, November), winter (December, January, February), spring (March, April, May) and summer (June, July, August). During the 1 year experiment all semen quality parameters showed a clear seasonal pattern. The volume, total sperm count and motility in fresh semen were significantly higher (P<0.05) in summer than in winter, while sperm concentration was significantly lower in summer compared to the other seasons. Regarding morphology, normal sperm was significantly lower (P<0.05) in summer than at any other time of the year and higher values (P<0.05) were found for major defects in summer than in spring and autumn. In frozen-thawed semen motility was significantly (P<0.05) improved in autumn when compared to spring and summer. Viability was lowest in summer and differed significantly (P<0.05) from other seasons. The HOS test revealed significantly more (P<0.05) membrane damaged spermatozoa in winter than in spring, summer and autumn. Our results demonstrate that in our climatic conditions clear seasonal differences occur in semen quality of fresh and frozen-thawed semen and that cryopreservation of stallion semen should preferably be performed in autumn.
Publication Date: 2003-05-24 PubMed ID: 12763159DOI: 10.1016/s0093-691x(03)00046-3Google Scholar: Lookup
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- Comparative Study
- Journal Article
Summary
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This research examines the seasonal variations in the quality of semens in Warmblood stallions and recommends the best period for semen cryopreservation. The study discovered that the quality of stallion semen varies with different seasons, and they found that autumn was the most preferable season for semen cryopreservation due to the improved quality and lower damage to the spermatozoa.
Research Methodology
- The researchers used 10 Warmblood stallions from the National Stud Farm in Avenches, Switzerland for their experiment.
- The semen was collected and frozen every other week for a year, from January to December 1999.
- The semen was evaluated based on volume, concentration, motility, number of morphologically normal sperms, and sperms with major defects like abnormal heads, acrosome defects, nuclear vacuoles, proximal droplets, abnormal midpieces.
- All the frozen-thawed semen samples were tested for motility and viability, and they also conducted the hypoosmotic swelling test (HOS) to determine potential damage to the spermatozoa.
- The year was divided into four seasons each of three months to analyze the seasonal differences in the semen quality.
Research Findings
- The researchers noted that the volume, total sperm count and motility in fresh semen were significantly higher in summer than in winter, whereas sperm concentration was significantly lower in summer compared to the other seasons.
- The study also indicated that sperms with normal morphology were significantly lower (P<0.05) in summer than in any other season. Higher values were registered for major defects in the sperms during the summer season compared to spring and autumn.
- The study found that the motility in frozen-thawed semen was significantly improved during autumn compared to spring and summer.
- The semen viability was lowest during summer and was significantly different from that of other seasons. The HOS test also suggested more membrane damage to the sperms during winter than in other seasons.
Conclusion
- Based on the research findings, the researchers concluded that there are significant seasonal differences in the quality of fresh and frozen-thawed semen under their climatic conditions.
- Given that the study revealed significant improvements in frozen-thawed semen motility during autumn compared to other seasons, the researchers recommended autumn as the best season to undertake semen cryopreservation in Warmblood stallions within their climatic conditions.
Cite This Article
APA
Janett F, Thun R, Niederer K, Burger D, Hässig M.
(2003).
Seasonal changes in semen quality and freezability in the Warmblood stallion.
Theriogenology, 60(3), 453-461.
https://doi.org/10.1016/s0093-691x(03)00046-3 Publication
Researcher Affiliations
- Clinic of Reproduction, University of Zurich, Winterthurerstrasse 260, 8057 Zürich, Switzerland. fjanett@vetclinics.unizh.ch
MeSH Terms
- Acrosome / ultrastructure
- Animals
- Climate
- Cryopreservation / veterinary
- Horses / physiology
- Hot Temperature
- Humidity
- Male
- Seasons
- Semen / physiology
- Semen Preservation / veterinary
- Sperm Count
- Sperm Motility
- Spermatozoa / abnormalities
- Spermatozoa / ultrastructure
- Temperature
Citations
This article has been cited 14 times.- Carvalho JC, Carvalho MG, Codognoto VM, Camargo LS, Kasimanickam R, Kastelic J, de Souza FF, Pinheiro Ferreira JC. Seasonal Changes in the Seminal Plasma Proteome of the Crab-Eating Fox (Cerdocyon thous). J Proteome Res 2026 Feb 6;25(2):723-734.
- Boni R, Ruggiero R, De Luca F, Serritella ML, Di Palma T, Cecchini Gualandi S. Repeatability of Selected Parameters Related to Stallion Sperm Quality and Cryotolerance. Animals (Basel) 2025 Sep 26;15(19).
- Bodu M, Hitit M, Greenwood OC, Murray RD, Memili E. Extender development for optimal cryopreservation of buck sperm to increase reproductive efficiency of goats. Front Vet Sci 2025;12:1554771.
- Dziekońska A, Szczepańska A, Wysokińska A. Effect of Season on the Characteristics of Warmblood Stallion Spermatozoa Stored in a Liquid State at 5 °C. Animals (Basel) 2025 Apr 3;15(7).
- Al-Kass Z, Morrell JM. Freezing Stallion Semen-What Do We Need to Focus on for the Future?. Vet Sci 2024 Feb 2;11(2).
- Egyptien S, Deleuze S, Ledeck J, Ponthier J. Sperm Quality Assessment in Stallions: How to Choose Relevant Assays to Answer Clinical Questions. Animals (Basel) 2023 Oct 6;13(19).
- Podico G, Spencer KM, Magalhaes HB, Canisso IF. Semen Quality of the First and Second Ejaculates Collected from Breeding Inactive Stallions after Cooling and Freezing. Vet Sci 2023 Feb 21;10(3).
- Senra RL, Ramírez-López CJ, Magalhães-Júnior MJ, Neves JGDS, Barros E, Waddington B, Guimarães SEF, Guimarães JD, Baracat-Pereira MC. Kallikrein proteoforms and reproductive parameters in stallion are conditioned by climate. Sci Rep 2022 Nov 4;12(1):18690.
- Ciani F, Maruccio L, Cocchia N, d'Angelo D, Carotenuto D, Avallone L, Namagerdi AA, Tafuri S. Antioxidants in assisted reproductive technologies: An overview on dog, cat, and horse. J Adv Vet Anim Res 2021 Mar;8(1):173-184.
- Suliman Y, Becker F, Tuchscherer A, Wimmers K. Seasonal variations in quantitative and qualitative sperm characteristics in fertile and subfertile stallions. Arch Anim Breed 2020;63(1):145-154.
- Johannisson A, Al-Essawe EM, Al-Saffar AK, Karkehabadi S, Lima-Verde I, Wulf M, Aurich C, Morrell JM. Season does not have a deleterious effect on proportions of stallion seminal plasma proteins. J Reprod Dev 2020 Jun 12;66(3):215-221.
- García MF, Nuñez Favre R, Stornelli MC, Rearte R, García Mitacek MC, de la Sota RL, Stornelli MA. Relationship between semen quality and seminal plasma cholesterol, triacylglycerols and proteins in the domestic cat. J Feline Med Surg 2020 Oct;22(10):882-889.
- Leme DP, Papa FO, Roser JF. Reproductive characteristics of stallions during the breeding and non-breeding season in a tropical region. Trop Anim Health Prod 2012 Oct;44(7):1703-7.
- Morrell JM, Johannisson A, Dalin AM, Hammar L, Sandebert T, Rodriguez-Martinez H. Sperm morphology and chromatin integrity in Swedish warmblood stallions and their relationship to pregnancy rates. Acta Vet Scand 2008 Jan 7;50(1):2.
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