Insemination of mares with low numbers of either unsexed or sexed spermatozoa.
Abstract: Two experiments were conducted to determine pregnancy rates in mares inseminated 1) with 5, 25 and 500 x 10(6) progressively motile spermatozoa (pms), or 2) with 25 x 10(6) sex-sorted cells. In Experiment 1, mares were assigned to 1 of 3 treatments: Group 1 (n=20) was inseminated into the uterine body with 500 x 10(6) pms. Group 2 (n=21) and Group 3 (n=20) were inseminated into the tip of the uterine horn ipsilateral to the preovulatory follicle with 25 and 5 x 10(6) pms, respectively. Mares in all 3 groups were inseminated either 40 (n=32) or 34 h (n=29) after GnRH administration. More mares became pregnant when inseminated with 500 x 10(6) (18/20 = 90%) than with 25 x 10(6) pms (12/21 = 57%; P0.1). In Experiment 2, mares were assigned to 1 of 2 treatments: Group A (n=11) was inseminated with 25 x 10(6) spermatozoa sorted into X and Y chromosome-bearing populations in a skimmilk extender. Group B (n=10) mares were inseminated similarly except that spermatozoa were sorted into the skimmilk extender + 4% egg yolk. Inseminations were performed 34 h after GnRH administration. Freshly collected semen was incubated in 224 microM Hoechst 33342 at 400 x 10(6) sperm/mL in HBGM-3 for 1 hr at 35 degrees C and then diluted to 100 x 10(6) sperm/mL for sorting. Sperm were sorted by sex using flow cytometer/cell sorters. Spermatozoa were collected at approximately 900 cells/sec into either the extender alone (Group A) or extender + 4% egg yolk (Group B), centrifuged and suspended to 25 x 10 sperm/mL and immediately inseminated. Pregnancy rates were similar (P>0.1) between the sperm treatments (extender alone = 13/10, 30% vs 4% EY + extender = 5/10, 50%). Based on ultrasonography, fetal sex at 60 to 70 d correlated perfectly with the sex of the sperm inseminated, demonstrating that foals of predetermined sex can be obtained following nonsurgical insemination with sexed spermatozoa.
Publication Date: 2000-06-01 PubMed ID: 10832757DOI: 10.1016/S0093-691X(00)00276-4Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research focuses on evaluating the pregnancy rates in mares when inseminated with varying amounts of motile spermatozoa as well as with sex-sorted spermatozoa. The results show that higher amounts increase pregnancy rates, but similar rates are observed when inseminating with small amounts. Also, it was successful in producing foals of predetermined sex using sex-sorted spermatozoa.
Research Methodology
- The research involved two experiments. The first experiment evaluated the pregnancy rates in mares inseminated with differing amounts of progressively motile spermatozoa (5, 25 and 500 x 10^6).
- The mares were divided into three groups based on the amount of spermatozoa used for insemination: 500 x 10^6 in Group 1, while 25 x 10^6 and 5 x 10^6 were used for Group 2 and 3, respectively.
- All mares were inseminated either 34 or 40 hours after receiving Gonadotropin-Releasing Hormone (GnRH).
- The second experiment involved inseminating mares with 25 x 10^6 sex-sorted spermatozoa.
- These mares were split into two groups, with Group A receiving spermatozoa sorted in a skimmilk extender and Group B receiving sperm sorted into the skimmilk extender with an additional 4% egg yolk.
- The sperm sorting was performed using flow cytometer/cell sorters.
Findings
- From the first experiment, more mares became pregnant when inseminated with 500 x 10^6 spermatozoa versus 25 x 10^6, but the results between the second and third groups that received 25 x 10^6 and 5 x 10^6 spermatozoa were similar.
- In the second experiment, the pregnancy rates between mares that received sperm in extenders alone and those that received sperm in the extender with egg yolk were also similar.
- On a unique note, foals were successfully born in predicted sex using sexed spermatozoa, demonstrating the feasibility of achieving foals of predetermined sex using non-surgical insemination methods.
Conclusion
- The study concludes that while increasing the number of spermatozoa can improve pregnancy rates, similar rates can be achieved with lower amounts.
- Furthermore, the research effectively demonstrated the potential for producing foals of a predetermined sex using sex-sorted spermatozoa.
Cite This Article
APA
Buchanan BR, Seidel GE, McCue PM, Schenk JL, Herickhoff LA, Squires EL.
(2000).
Insemination of mares with low numbers of either unsexed or sexed spermatozoa.
Theriogenology, 53(6), 1333-1344.
https://doi.org/10.1016/S0093-691X(00)00276-4 Publication
Researcher Affiliations
- Animal Reproduction and Biotechnology Laboratory, Colorado State University, Fort Collins 80523, USA.
MeSH Terms
- Animals
- Cell Separation
- Female
- Gonadotropin-Releasing Hormone / administration & dosage
- Horses
- Insemination, Artificial / methods
- Insemination, Artificial / veterinary
- Male
- Ovulation
- Pregnancy
- Sex Determination Processes
- Sperm Count
Citations
This article has been cited 6 times.- Peng J, Hou Y, Wu S, Li Z, Wu Z. Knockout of Rlim Results in a Sex Ratio Shift toward Males but Superovulation Cannot Compensate for the Reduced Litter Size. Animals (Basel) 2023 Mar 17;13(6).
- Orsolini MF, Meyers SA, Dini P. An Update on Semen Physiology, Technologies, and Selection Techniques for the Advancement of In Vitro Equine Embryo Production: Section II. Animals (Basel) 2021 Nov 20;11(11).
- Camara Pirez M, Steele H, Reese S, Kölle S. Bovine sperm-oviduct interactions are characterized by specific sperm behaviour, ultrastructure and tubal reactions which are impacted by sex sorting. Sci Rep 2020 Oct 5;10(1):16522.
- Umehara T, Tsujita N, Zhu Z, Ikedo M, Shimada M. A simple sperm-sexing method that activates TLR7/8 on X sperm for the efficient production of sexed mouse or cattle embryos. Nat Protoc 2020 Aug;15(8):2645-2667.
- Hou Y, Peng J, Hong L, Wu Z, Zheng E, Li Z. Gender Control of Mouse Embryos by Activation of TLR7/8 on X Sperm via Ligands dsRNA-40 and dsRNA-DR. Molecules 2024 Jan 4;29(1).
- Quelhas J, Pinto-Pinho P, Lopes G, Rocha A, Pinto-Leite R, Fardilha M, Colaço B. Sustainable animal production: exploring the benefits of sperm sexing technologies in addressing critical industry challenges. Front Vet Sci 2023;10:1181659.
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