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Equine veterinary journal2024; doi: 10.1111/evj.14073

Effects of repeated embryo flushing without PGF2α administration on luteal function, percentage of unwanted pregnancy and subsequent fertility in mares.

Abstract: PGF is commonly given at the end of embryo flushing (EF) to shorten the interval to the next oestrus and ovulation. Objective: To determine the effect of repeated EF on plasma progesterone concentration, percentage of mares with endometritis, unwanted pregnancy and subsequent fertility in mares flushed without the use of PGF . Methods: Controlled experiments. Methods: Nine mares were inseminated in seven consecutive cycles (n = 63), to either perform an EF (n = 54) 7-9 days after ovulation or left pregnant (n = 9). PGF was not used to induce oestrus. Ultrasound examination and blood sampling were performed just before the EF and 72 h later to determine changes in progesterone concentration and signs of endometritis. Results: The overall percentage of positive EF/pregnancy was 55.5% (30/54) and 66.7% (6/9), respectively. The likelihood of pregnancy/positive EF in the first three cycles was 55.5% (15/29). This was not different (p > 0.1) from the fertility of the last four cycles (69.4%, 25/36). In five EF cycles (9.3%), mares had signs of endometritis and early luteolysis (progesterone <2 ng/mL) 72 h after EF. The reduction in progesterone concentration by 72 h after EF was greater (p < 0.05) for Day 9 (-2.3 ± 0.7 ng/mL) than Day 7 (-1.0 ± 0.8 ng/mL) or Day 8 (-1.3 ± 1.1 ng/mL) cycles. The progesterone concentration in non-flushed mares did not vary significantly during the sampled period (Day 7-12). There were 5 cycles in which the donor mare remained pregnant after the EF, although four were from a single mare. Conclusions: The mare population was limited to barren and maiden mares. The cycle order and operator allocation to each EF were not randomised. Conclusions: EF induces a subtle, but significant reduction in progesterone concentrations compared with non-EF cycles. However, the percentage of mares with EF-induced full luteolysis is low (9.3%). The fertility of mares after repeated EF without administration of PGF was unaffected; however, there is a considerable risk of unwanted pregnancy (5/27 = 18.5%) in donors from which an embryo was not recovered.
© 2024 The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.
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Publication Date: 2024-02-25 PubMed ID: 38403412DOI: 10.1111/evj.14073Google Scholar: Lookup
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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 conducted an investigation on the effect of repeated embryo flushing in mares, without the use of a common drug, PGF. It focused on the impact this has on mares’ luteal function, fertility, and the risk of unwanted pregnancies.

Objective of The Research

  • This study aimed to understand the impact of repeated embryo flushing (EF) on aspects of mares’ reproduction such as the concentration of plasma progesterone, the incidence of endometritis (uterus inflammation), and unwanted pregnancies. The aim was also to determine the fertility of mares after several EF procedures carried out without administering PGF, a hormone typically used to induce oestrus (the period when mares are receptive to mating).

Methods Used

  • In this experimental study, nine mares were inseminated over seven cycles. EF was conducted 7–9 days post-ovulation for 54 cycles, while 9 cycles were kept pregnant.
  • Ultrasound examinations and blood samples were taken before the EF and 72 hours later. These tests were performed to monitor changes in progesterone levels (a hormone significant for pregnancy maintenance) and to check for signs of endometritis.

Key Findings

  • The overall rate of positive EF or pregnancy was 55.5% for the 54 EF cycles and 66.7% for the 9 pregnancy cycles. There was no significant difference in positive EF or pregnancies between the first three and last four cycles.
  • In 5 out of 54 EF cycles (9.3%), mares showed signs of endometritis and early luteolysis (the disappearance of the corpus luteum, a temporary endocrine gland involved in ovarian cycles and pregnancy) 72 hours after EF.
  • Progesterone levels dropped more on Day 9 after EF than on Day 7 or 8. Notably, the progesterone levels in mares that did not undergo EF remained constant throughout the sampled period.
  • Five cycles resulted in the donor mare remaining pregnant after EF, with four of these from the same mare.

Conclusions

  • In conclusion, this study implies that EF causes minor but significant reductions in progesterone levels compared to non-EF cycles. However, only a small percentage (9.3%) of mares undergo full luteolysis after EF.
  • The fertility rate of mares is not affected by repeated EF without administering PGF.
  • But, there is a substantial risk (18.5%) of unwanted pregnancies in donor mares from which an embryo was not recovered.

Cite This Article

APA
Martínez-Boví R, Sala-Ayala L, Querol-Paajanen A, Plaza-Dávila M, Cuervo-Arango J. (2024). Effects of repeated embryo flushing without PGF2α administration on luteal function, percentage of unwanted pregnancy and subsequent fertility in mares. Equine Vet J. https://doi.org/10.1111/evj.14073

Publication

Equine veterinary journal
ISSN: 2042-3306
NlmUniqueID: 0173320
Country: United States
Language: English

Researcher Affiliations

Martínez-Boví, Rebeca
  • Equine Fertility Group, Faculty of Veterinary Medicine, Universidad CEU Cardenal Herrera, CEU Universities, Alfara del Patriarca, Valencia, Spain.
Sala-Ayala, Laura
  • Equine Fertility Group, Faculty of Veterinary Medicine, Universidad CEU Cardenal Herrera, CEU Universities, Alfara del Patriarca, Valencia, Spain.
Querol-Paajanen, Aurora
  • Equine Fertility Group, Faculty of Veterinary Medicine, Universidad CEU Cardenal Herrera, CEU Universities, Alfara del Patriarca, Valencia, Spain.
Plaza-Dávila, María
  • Equine Fertility Group, Faculty of Veterinary Medicine, Universidad CEU Cardenal Herrera, CEU Universities, Alfara del Patriarca, Valencia, Spain.
Cuervo-Arango, Juan
  • Equine Fertility Group, Faculty of Veterinary Medicine, Universidad CEU Cardenal Herrera, CEU Universities, Alfara del Patriarca, Valencia, Spain.

Grant Funding

  • INDI-22/12 / Universidad CEU Cardenal Herrera

References

This article includes 30 references
  1. Stout TAE. Clinical insights: assisted reproductive technologies.. Equine Vet J 2019;51(4):427-428.
  2. Hinrichs K. Assisted reproductive techniques in mares.. Reprod Domest Anim 2018;53(S2):4-13.
  3. Squires EL, Carnevale EM, McCue PM, Bruemmer JE. Embryo technologies in the horse.. Theriogenology 2003;59(1):151-170.
  4. Hartman DL. Embryo transfer: donor mare management after the flush.. 2011. p. 2878-2879.
  5. McCue PM, Squires EL. Equine embryo transfer.. 2015.
  6. Dordas-Perpinya M, Bruyas JF. Practical aspects of embryo transfer.. Transl Res Vet Sci 2019;2(1):23-39.
  7. Pietrani M, Losinno L, Cuervo-Arango J. Effect of the interval from prostaglandin f2alpha treatment to ovulation on reproductive efficiency rates in a commercial equine embryo transfer program.. J Equine Vet Sci 2019;78:123-126.
  8. Burden CA, McCue PM, Ferris RA. Effect of cloprostenol administration on interval to subsequent ovulation and anovulatory follicle formation in quarter horse mares.. J Equine Vet Sci 2015;35:531-535.
  9. Cuervo-Arango J, Mateu-Sánchez S, Aguilar JJ, Nielsen JM, Etcharren V, Vettorazzi ML. The effect of the interval from PGF treatment to ovulation on embryo recovery and pregnancy rate in the mare.. Theriogenology 2015;83(8):1272-1278.
  10. Handler J, Königshofer M, Kindahl H, Schams D, Aurich C. Secretion patterns of oxytocin and PGF2alpha-metabolite in response to cervical dilatation in cyclic mares.. Theriogenology 2003;59(5-6):1381-1391.
  11. Betteridge KJ, Renard A, Goff AK. Uterine prostaglandin release relative to embryo collection, transfer procedures and maintenance of the corpus luteum.. Equine Vet J 1985;17:25-33.
  12. Wilde MH, Dinger JE, Hoagland TA, Graves-Hoagland RL, Woody CO. The effects of cervical dilation on plasma PGFM, progesterone and the duration of luteal function in diestrous mares.. Theriogenology 1989;32(4):675-681.
  13. Handler J, Hoffmann D, Weber F, Schams D, Aurich C. Oxytocin does not contribute to the effects of cervical dilation on progesterone secretion and embryonic development in mares.. Theriogenology 2006;66(5):1397-1404.
  14. Rubio MS, Allen WR, Wilsher S, Mouguelar H. Effects of embryo flushing on serum progesterone levels and the inter-ovulatory period in Arabian donor mares.. J Equine Vet Sci 2023;125:103.
  15. Silva ESM, Newcombe JR, Cuervo-Arango J. The effect of treatment with oestradiol benzoate on oestrus expression and endometrial oedema in anovulatory and cyclic mares.. Animals (Basel) 2023;13(5):938.
  16. Cuervo-Arango J, Newcombe JR. Repeatability of preovulatory follicular diameter and uterine edema pattern in two consecutive cycles in the mare and how they are influenced by ovulation inductors.. Theriogenology 2008;69(6):681-687.
  17. Cuervo-Arango J, Martín-Peláez MS, Claes AN. A practical guide to estimate the age of the early CL by ultrasonography in mares examined for the first time to be used as recipients in a commercial embryo transfer program.. Theriogenology 2020;153:48-53.
  18. Ginther OJ. Prolonged luteal activity in mares-a semantic quagmire.. Equine Vet J 1990;22(3):152-156.
  19. Pelehach LM, Greaves HE, Porter MB, Desvousges A, Sharp DC. The role of estrogens and progesterone in the induction and dissipation of uterine edema in mares.. Theriogenology 2002;54:441-444.
  20. Allen WE, Hadley JC. Blood progesterone concentrations in pregnant and non-pregnant mares.. Equine Vet J 1974;6(2):87-93.
  21. Lagneaux P, Tainturier D, Palmer E. Luteolysis and bacterial contamination associated with unsuccessful cervical embryo transfer in the mare.. Theriogenology 1988;29:285.
  22. Cuervo-Arango J, Newcombe JR. Relationship between dose of cloprostenol and age of corpus luteum on the luteolytic response of early dioestrous mares: a field study.. Reprod Domest Anim 2012;47(4):660-665.
  23. Bergfelt DR, Pierson RA, Ginther OJ. Regression and resurgence of the CL following PGF2alpha treatment 3 days after ovulation in mares.. Theriogenology 2006;65(8):1605-1619.
  24. Battut I, Colchen S, Fieni F, Tainturier D, Bruyas JF. Success rates when attempting to nonsurgically collect equine embryos at 144, 156 or 168 hours after ovulation.. Equine Vet J Suppl 1997;25:60-62.
  25. Cuervo-Arango J, Aguilar J, Newcombe JR. Effect of type of semen, time of insemination relative to ovulation and embryo transfer on early equine embryonic vesicle growth as determined by ultrasound.. Theriogenology 2009;71(8):1267-1275.
  26. Aurich C, König N, Budik S. Effects of repeated embryo collection on embryo recovery rate in fertile mares.. Reprod Domest Anim 2011;46(3):419-422.
    doi: 10.1111/j.1439-0531.2010.01682.xgoogle scholar: lookup
  27. Squires EL, Imel KJ, Iuliano MF, Shideler RK. Factors affecting reproductive efficiency in an equine embryo transfer programme.. J Reprod Fertil Suppl 1982;32:409-414.
  28. Carnevale EM, Beisner AE, McCue P, Bass LD, Squires EL. Uterine changes associated with repeated inseminations and embryo collections in mares.. 2005.
  29. Cuervo-Arango J, Claes AN, Stout TAE. The recipient's Day after ovulation and the number of corpora lutea influence the likelihood of pregnancy in mares following transfer of ICSI frozen embryos.. Theriogenology 2019;135:181-188.
  30. Newcombe JR, Wilsher S, Cuervo-Arango J. The post-ovulatory rise in progesterone is lower and the persistence of oestrous behaviour longer during the first compared with the second cycle of the breeding season in mares.. Reprod Domest Anim 2023;58:141-145.

Citations

This article has been cited 2 times.
  1. Alkhadrawy JMH, Aboelmaaty AM, Abou-Ahmed MM, Ghallab AM. Effect of hCG and prostaglandin on ovarian, luteal development, and hormonal changes in embryo donor mares during the hot summer months in subtropics. Open Vet J 2024 Aug;14(8):2057-2072.
    doi: 10.5455/OVJ.2024.v14.i8.35pubmed: 39308718google scholar: lookup
  2. Martínez-Boví R, Gaber JTH, Sala-Ayala L, Plaza-Dávila M, Cuervo-Arango J. Pregnancy and Luteal Responses to Embryo Reinsertion following Embryo Flushing in Donor Mares. Animals (Basel) 2024 May 29;14(11).
    doi: 10.3390/ani14111605pubmed: 38891652google scholar: lookup
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