Effects of semen fractionation and dilution ratio on equine spermatozoal motility parameters.
Abstract: Two experiments were conducted to examine the effects of semen fractionation and dilution ratio on motility parameters of stallion spermatozoa. In Experiment 1, three ejaculates from each of three stallions were divided into sperm-rich (SR) and sperm-poor (SP) fractions to determine the difference in sperm concentration. Mean sperm concentration in SR fractions (349.5 x 10(6)/ml) was greater (P < 0.001) than that of SP fractions (96.9 x 10(6)/ml). In Experiment 2, three ejaculates from each of two stallions were divided into SR and SP fractions. Fifty percent of the original volume of SR fractions was combined with 50% of the original volume of SP fractions for each ejaculate to represent total ejaculates. SR and total ejaculates were diluted with skim milk-glucose semen extender as follows: 1) no dilution, or dilution to 2) 100 x 10(6)sperm/ml, 3) 50 x 10(6)sperm/ml, or 4) 25 x 10(6)sperm/ml. Semen samples were evaluated at 0.5, 3, 6, 12, and 24 h postejaculation (25 degrees C storage temperature) for percentages of total spermatozoal motility (TSM) and progressive spermatozoal motility (PSM). Mean TSM was greater (P < 0.05) in SR ejaculates than total ejaculates at 12 and 24 h postejaculation. Mean TSM of undiluted semen was lower (P < 0.05) than other dilution ratios over all periods. Mean TSM was greater (P < 0.05) at a 25 x 10(6)sperm/ml dilution ratio than a 50 x 10(6)sperm/ml dilution ratio at 12 and 24 h postejaculation, and greater (P < 0.05) than a 100 x 10(6)sperm/ml dilution ratio from 3 to 24 h postejaculation. Similar patterns were found for PSM. Collection of SR ejaculates and dilution to 25 x 10(6)sperm/ml improved longevity of spermatozoal motility.
Publication Date: 1987-11-01 PubMed ID: 16726354DOI: 10.1016/0093-691x(87)90288-3Google Scholar: Lookup The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
This research investigates how the division of semen into sperm-rich and sperm-poor fractions and the dilution ratio can affect the motility, or movements, of stallion sperm. The findings indicate that sperm-rich ejaculates maintained higher motility than total ejaculates over time, and the optimal dilution ratio for sustaining sperm motility was found to be 25 million sperm per milliliter.
Research Objectives and Methodology
- The researchers intended to clarify the impacts of semen fractionation (dividing semen into sperm-rich and sperm-poor sections) and dilution ratio on the mobility parameters of stallion spermatozoa.
- Two experiments were performed, the first one focused on understanding the difference in sperm concentration between sperm-rich (SR) and sperm-poor (SP) fractions. The second experiment was designed to investigate the effect of different dilution ratios on sperm motility.
Key Findings
- The results from experiment 1 revealed that the sperm concentration was significantly greater in sperm-rich fractions than in sperm-poor fractions.
- The second experiment indicated that sperm motility was higher in sperm-rich ejaculates compared to total ejaculates (a combination of SR and SP fractions) at 12 and 24 hours after ejaculation.
- It was also observed that undiluted semen had lower motility compared to other dilution ratios over all periods.
- Further, sperm motility was higher with a dilution ratio of 25 million sperm per milliliter than 50 million sperm per milliliter at the same post-ejaculation intervals, and greater than a ratio of 100 million sperm per milliliter from 3 to 24 hours post-ejaculation. Similar patterns were observed for progressive spermatozoal motility, which refers to the efficient forward movement of sperm.
Conclusion
- The research concluded that collecting sperm-rich ejaculates and diluting them to a ratio of 25 million sperm per milliliter improves the longevity of sperm motility. This can have important implications for artificial insemination processes in horses.
Cite This Article
APA
Varner DD, Blanchard TL, Love CL, Garcia MC, Kenney RM.
(1987).
Effects of semen fractionation and dilution ratio on equine spermatozoal motility parameters.
Theriogenology, 28(5), 709-723.
https://doi.org/10.1016/0093-691x(87)90288-3 Publication
Researcher Affiliations
- Department of Large Animal Medicine and Surgery, Texas Veterinary Medical Center, Texas A&M University, College Station, TX, USA.
Citations
This article has been cited 9 times.- Brito LFC, Linardi RL, Rosales LAS, Balamurugan NS, Hernández-Avilés C, Ramírez-Agámez L. Evaluation of a Chemically Defined, Long-Term Extender for Liquid Storage of Stallion Semen. Reprod Domest Anim 2025 Sep;60(9):e70126.
- Gacem S, Mocé E, Gozalbo C, Albuixech-Benetó M, Esteve IC, Martínez-Talaván A, Silvestre MA. The Effects of Extender Energetic Substrate Type on Goat Sperm Stored at 17 °C. Biology (Basel) 2025 Jun 27;14(7).
- Miró J, Martínez-Rodero I, Yeste M, Catalán J. Cryopreservation of Horse Sperm. Methods Mol Biol 2025;2897:193-206.
- Sugai N, Werre S, Cecere JT, Balogh O. Comparing different sperm concentrations for optimizing cooled semen use in the dog. Front Vet Sci 2023;10:1339840.
- Madeddu M, Marelli S, Abdel Sayed A, Mosca F, Cerolini S, Zaniboni L. Assessment of Sperm Viability and Computer-Assisted Motility Analysis in Budgerigars (Melopsittacus undulatus): Effect of Several In Vitro Processing Conditions. Vet Med Int 2022;2022:5997320.
- Ramirez-Perez H, Guerrero-Netro HM, Torres-Rodríguez P, Díaz-Durán M, Boeta-Acosta AM, Diaw M. A combination of taurine and caffeine maintains sperm quality in equine semen during chilled storage. J Adv Vet Anim Res 2021 Dec;8(4):635-641.
- Gacem S, Catalán J, Valverde A, Soler C, Miró J. Optimization of CASA-Mot Analysis of Donkey Sperm: Optimum Frame Rate and Values of Kinematic Variables for Different Counting Chamber and Fields. Animals (Basel) 2020 Oct 29;10(11).
- Buss T, Aurich J, Aurich C. Evaluation of a portable device for assessment of motility in stallion semen. Reprod Domest Anim 2019 Mar;54(3):514-519.
- Morrell JM, Johannisson A. Comparison of the Effect of Heterologous and Homologous Seminal Plasma on Motility and Chromatin Integrity of Stallion Spermatozoa Selected by Single Layer Centrifugation. J Vet Med 2014;2014:325451.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists