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Reproduction in domestic animals = Zuchthygiene2025; 60(3); e70043; doi: 10.1111/rda.70043

Transvaginal Follicle Aspiration in Mares: A Description of Different Techniques and Comparison of Results Across Different OPU Clinics.

Abstract: This retrospective clinical study describes different techniques for transvaginal follicle aspiration in mares and compares results from 5 different commercial ovum pick-up (OPU) clinics in which the same operator aspirated mares using different systems and equipment: Clinic 1 (n = 42 mares, two-operator OPU technique, double-lumen-echogenic-tip needle, and manual syringe-assisted flushing of follicles), Clinic 2 (n = 28 mares, single-operator-OPU-technique, double-lumen-echogenic-tip needle, infusion pump controlled by foot-pedal for follicle flushing), Clinic 3 (n = 18 mares, single-operator-OPU-technique, double-lumen-echogenic-tip needle, and manual syringe-assisted flushing of follicles), Clinic 4 (n = 24 mares, single-operator-OPU-technique, double-lumen-non-echogenic-tip needle, and manual syringe-assisted flushing of follicles), and Clinic 5 (n = 9 mares, aspirated as in Clinic 1). The ease of performing OPU (visibility of needle tip and difficulty to hold ovary, probe, and needle) and the mean number of recovered oocytes were compared between clinics. The mean number of recovered oocytes per mare and oocytes per follicle for clinics 1-5 were 11.9 ± 4.6 and 64%, 13.5 ± 6.5 and 53%, 12.3 ± 4.2 and 54%, 9.5 ± 3.3 and 51%, and 19.9 ± 8.2 and 64%, respectively. The combined recovered oocyte per aspirated follicle was 10% higher in clinics with a 2-operator technique (clinic 1 and 5, 63.63%) than in clinics with the single-operator technique (clinics 2-4, 53.32%). The mean number of recovered oocytes was numerically greater in the clinics using the echogenic needle tip (11.9, 13.5, 12.3, and 19.9 oocytes per mare, for clinics 1, 2, 3, and 5, respectively) than in the clinic using the non-echogenic needle tip; (9.5 oocytes per mare for clinic 4). The use of a plastic syringe or an infusion pump to flush follicles did not appear to affect the number of recovered oocytes or oocyte recovery rate (clinic 2 vs. 3). The left arm of the single operator (holding OPU probe and needle) experienced fatigue more frequently when mares were aspirated singly, than when the needle was managed by a second operator. In conclusion, the oocyte per follicle recovery was 10% lower in clinics using a single-operator-OPU-technique compared with clinics using a two-operator-technique.
© 2025 Wiley‐VCH GmbH. Published by John Wiley & Sons Ltd.
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Publication Date: 2025-03-09 PubMed ID: 40056006DOI: 10.1111/rda.70043Google Scholar: Lookup
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  • Journal Article
  • Comparative Study

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.

The research is about comparing the efficiency and yield of different transvaginal follicle aspiration methods used in multiple ovum pick-up (OPU) clinics where horses are aspirated. It reveals that a two-operator technique yields 10% more oocytes per aspirated follicle than the single-operator technique.

Study Design

  • This retrospective clinical study was carried out in five different OPU clinics. All clinics used the same operator but employed different systems and equipment.
  • Between 9 and 42 mares were examined in each clinic, using a variety of equipment including double-lumen-echogenic-tip needles, a non-echogenic-tip needle, a foot-pedal-controlled infusion pump for follicle flushing, and a manual syringe-assisted follicle flushing system.
  • The OPU procedure was performed either by a single operator or by two operators.

Comparison of Results

  • The number of retrieved oocytes was compared between the clinics. It was identified that the average number of oocytes recovered ranged from 9.5 to 19.9 oocytes per mare across all the clinics.
  • The study identified a 10% increase in oocyte yield at clinics using a two-operator approach compared to those using a single-operator approach.
  • The use of an echogenic needle tip might have contributed to a slightly higher yield of oocytes in comparison to a non-echogenic one.
  • There was no significant difference in oocyte recovery when comparing the use of a plastic syringe or an infusion pump for follicle flushing.
  • Fatigue was more commonly observed in the single-operator procedure, particularly in the left arm managing the OPU probe and needle.

Conclusion

  • The study concludes that the two-operator technique provided a 10% higher yield of oocytes per follicle than the single-operator technique.
  • This result emphasized the importance of method selection during transvaginal follicle aspiration in mares, which could have significant implications for fields like animal husbandry and related medical practices.

Cite This Article

APA
Cuervo-Arango J, Necchi D, Clutton-Brock A, Profaska M, Crabtree J, Claes A. (2025). Transvaginal Follicle Aspiration in Mares: A Description of Different Techniques and Comparison of Results Across Different OPU Clinics. Reprod Domest Anim, 60(3), e70043. https://doi.org/10.1111/rda.70043

Publication

Reproduction in domestic animals = Zuchthygiene
ISSN: 1439-0531
NlmUniqueID: 9015668
Country: Germany
Language: English
Volume: 60
Issue: 3
Pages: e70043

Researcher Affiliations

Cuervo-Arango, Juan
  • Equine Fertility Group, Facultad de Veterinaria, Universidad Cardenal Herrera-CEU, CEU Universities, Valencia, Spain.
Necchi, Denis
  • Keros Embryo Transfer Center, Zonnebeke, Belgium.
Clutton-Brock, Amber
  • Equibreed UK Ltd, Lower Meadows Grange Lane, Beenham, UK.
Profaska, Magdalena
  • Equibiotech sp. z o.o, Nowa Iwiczna, Poland.
  • Katedra Diagnostyki i Nauk Klinicznych, Wydział Medycyny Weterynaryjnej, Uniwersytet Rolniczy Im. Hugona Kołłątaja w Krakowie, Kraków, Poland.
Crabtree, James
  • Equine Reproductive Services (UK) ltd, Trigger Castle, North Yorkshire, UK.
Claes, Anthony
  • Department of Clinical Sciences, Utrecht University, Utrecht, the Netherlands.

MeSH Terms

  • Horses
  • Female
  • Animals
  • Retrospective Studies
  • Oocyte Retrieval / veterinary
  • Oocyte Retrieval / methods
  • Ovarian Follicle
  • Needles
  • Oocytes

References

This article includes 26 references
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Citations

This article has been cited 1 times.
  1. Márquez-Moya A, Carreras-Vico N, Sala-Ayala L, Martínez-Boví R, Cuervo-Arango J. Comparative Evaluation of Follicular Flushing Frequency and Scraping Time During Ovum Pick-Up in Mares: Effects on Oocyte Recovery Rate and Technical Considerations. Reprod Domest Anim 2026 Feb;61(2):e70183.
    doi: 10.1111/rda.70183pubmed: 41674388google scholar: lookup
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