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Acta veterinaria Scandinavica2006; 48(1); 12; doi: 10.1186/1751-0147-48-12

A preliminary study on the induction of dioestrous ovulation in the mare–a possible method for inducing prolonged luteal phase.

Abstract: Strong oestrous symptoms in the mare can cause problems with racing, training and handling. Since long-acting progesterone treatment is not permitted in mares at competition (e.g. according to FEI rules), there is a need for methods to suppress unwanted cyclicity. Spontaneous dioestrous ovulations in the late luteal phase may cause a prolongation of the luteal phase in mares. Methods: In this preliminary study, in an attempt to induce ovulation during the luteal phase, human chorionic gonadotropin (hCG) (3000 IU) was injected intramuscularly in four mares (experimental group) in the luteal phase when a dioestrous follicle > or = 30 mm was detected. A fifth mare included in this group was not treated due to no detectable dioestrous follicles > or = 30 mm. Four control mares were similarly injected with saline. The mares were followed with ultrasound for 72 hours post injection or until ovulation. Blood samples for progesterone analysis were obtained twice weekly for one month and thereafter once weekly for another two to four months. Results: Three of the hCG-treated mares ovulated within 72 hours after treatment and developed prolonged luteal phases of 58, 68 and 82 days respectively. One treated mare never ovulated after the hCG injection and progesterone levels fell below 3 nmol/l nine days post treatment. Progesterone levels in the control mares were below 3 nmol/l within nine days after saline injection, except for one mare, which developed a spontaneously prolonged luteal phase of 72 days. Conclusions: HCG treatment may be a method to induce prolonged luteal phases in the mare provided there is a dioestrous follicle > or = 30 mm that ovulates post-treatment. However, the method needs to be tested on a larger number of mares to be able to draw conclusions regarding its effectiveness.
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Publication Date: 2006-07-26 PubMed ID: 16987391PubMed Central: PMC1557516DOI: 10.1186/1751-0147-48-12Google Scholar: Lookup
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  • Comparative Study
  • 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.

The study explores the use of human chorionic gonadotropin (hCG) to induce prolonged luteal phases in mares, as a method to suppress reproductive cycles that can disrupt horse training and competition.

Research Context

The study is rooted in the issues that arise from strong oestrous symptoms in mares. These symptoms can interfere with the horse’s performance during races, training, or generally affect their behaviour. Prescriptive treatments like long-acting progesterone are not allowed in competition mares. Consequently, there is a necessity for alternative ways to suppress these disruptive cycles. One such approach investigated was the induction of dioestrous ovulations in the late luteal phase, which usually results in prolonged luteal phases for mares.

Methodology

  • The study experimented with human chorionic gonadotropin (hCG) to induce ovulation during the luteal phase.
  • An initial sample of four mares was selected and each received an intramuscular injection of 3000 IU hCG when a dioestrous follicle of equal to or more than 30 mm was identified.
  • A fifth mare in the study didn’t receive the treatment due to the absence of a large enough dioestrous follicle.
  • Four control mares were injected with saline in identical conditions.
  • Post-injection, the mares were monitored using ultrasound for 72 hours or until ovulation occurred.
  • Blood samples were taken twice weekly for a month, followed by once weekly for the next two to four months for progesterone analysis.

Results

  • Three of the four hCG-treated mares ovulated within 72 hours of treatment, resulting in prolonged luteal phases of 58, 68, and 82 days respectively.
  • One treated mare didn’t ovulate after the hCG injection and displayed progesterone levels below 3 nmol/l nine days post-treatment.
  • Among the control mares, progesterone levels fell below 3 nmol/l within nine days after saline injection, except for one mare that spontaneously developed a prolonged luteal phase of 72 days.

Conclusions and Recommendations

The study concluded that hCG treatment could be a viable method to induce prolonged luteal phases in mares when a dioestrous follicle of 30 mm or larger is present and ovulates post-treatment. However, the authors caution that more extensive experimentation with a larger sample size is needed to definitively establish the effectiveness of the method.

Cite This Article

APA
Hedberg Y, Dalin AM, Santesson M, Kindahl H. (2006). A preliminary study on the induction of dioestrous ovulation in the mare–a possible method for inducing prolonged luteal phase. Acta Vet Scand, 48(1), 12. https://doi.org/10.1186/1751-0147-48-12

Publication

Acta veterinaria Scandinavica
ISSN: 1751-0147
NlmUniqueID: 0370400
Country: England
Language: English
Volume: 48
Issue: 1
Pages: 12

Researcher Affiliations

Hedberg, Ylva
  • Division of Comparative Reproduction, Obstetrics and Udder Health, Department of Clinical Sciences, P,O, Box 7054, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden. ylva.hedberg@kv.slu.se
Dalin, Anne-Marie
    Santesson, Malin
      Kindahl, Hans

        MeSH Terms

        • Animals
        • Chorionic Gonadotropin / administration & dosage
        • Chorionic Gonadotropin / pharmacology
        • Diestrus / drug effects
        • Diestrus / physiology
        • Female
        • Horses / physiology
        • Injections, Intramuscular / veterinary
        • Luteal Phase / drug effects
        • Ovulation / drug effects
        • Ovulation Induction / veterinary
        • Progesterone / blood
        • Random Allocation
        • Sodium Chloride / pharmacology

        References

        This article includes 39 references
        1. Lindström C. Nymphomania in the mare. Master thesis. Swedish University of Agriculture, Faculty of Veterinary Medicine; 2000.
        2. Hedberg Y, Dalin AM, Ohagen P, Holm KR, Kindahl H. Effect of oestrous-cycle stage on the response of mares in a novel object test and isolation test.. Reprod Domest Anim 2005 Oct;40(5):480-8.
          doi: 10.1111/j.1439-0531.2005.00611.xpubmed: 16149956google scholar: lookup
        3. Tagbøl T, Andresen Ø, Thomassen R. Mild form of nymphomania in the horse. Effect of gestagen treatment in racehorses. Proceedings Nordic Mastitis and Reproduction Meeting: 1991; Trondheim Town. 1991. pp. 115–121.
        4. Christensson J. Effect of progesterone treatment in mild nymphomania in the mare. Svensk Veterinärtidning 1991;43:111–115.
        5. The British Jockey Club
        6. Swedish trotting association (STC)
        7. International Federation for Equestrian Sports (FEI)
        8. Swedish equestrian association (Svenska Ridsportförbundet)
        9. Lefranc AC, Allen WR. Nonpharmacological suppression of oestrus in the mare.. Equine Vet J 2004 Mar;36(2):183-5.
          pubmed: 15043003doi: 10.2746/0425164044868675google scholar: lookup
        10. Nie GJ, Johnson KE, Braden TD, Wenzel JGW. Modifying estrus behavior in mares- an alternative approach. Proceedings Annual Conference Society for Theriogenology: 12–15 September 2001; Vancouver. 2001. pp. 225–227.
        11. Rivera del Alamo MM, Reilas T, Katila T. Inhibition of oestrus in mares using intrauterine devices. Reprod Dom Anim 2005;40:343.
        12. Hughes JP, Marcelo AC, Stabenfeldt GH. Luteal phase ovulations: what are the options?. Proceedings of Annual Meeting of the Society of Theriogenology: 11–13 September 1985; Sacramento. 1985. pp. 123–125.
        13. Wesson JA, Ginther OJ. Influence of season and age on reproductive activity in pony mares on the basis of a slaughterhouse survey.. J Anim Sci 1981 Jan;52(1):119-29.
          pubmed: 7195392doi: 10.2527/jas1981.521119xgoogle scholar: lookup
        14. Douglas RH, Ginther OJ. Effects of prostaglandin F2alpha on estrous cycle or corpus luteum in mares and gilts.. J Anim Sci 1975 Mar;40(3):518-22.
          pubmed: 1167856doi: 10.2527/jas1975.403518xgoogle scholar: lookup
        15. Arthur GH. Influence of intrauterine saline infusion upon the oestrous cycle of the mare.. J Reprod Fertil Suppl 1975 Oct;(23):231-4.
          pubmed: 1060783
        16. Neely DP. Studies on the control of luteal function and prostaglandin release in the mare. PhD Thesis. University of California, Davis; 1979.
        17. Ginther OJ. Reproductive Biology of the Mare: Basic and Applied Aspects. 2. Wisconsin: Equiservices; 1992.
        18. Hughes JP, Stabenfeldt GH, Kennedy PC. The estrous cycle and selected functional and pathologic ovarian abnormalities in the mare.. Vet Clin North Am Large Anim Pract 1980 Nov;2(2):225-39.
          pubmed: 7233768doi: 10.1016/s0196-9846(17)30158-1google scholar: lookup
        19. Daels PF, McCue PM, DeMoraes MJ, Hughes JP. Persistence of the luteal phase following ovulation during altrenogest treatment in mares.. Theriogenology 1996 Oct 1;46(5):799-811.
          doi: 10.1016/S0093-691X(96)00238-5pubmed: 16727944google scholar: lookup
        20. Koskinen E, Lindeberg H, Kuntsi H, Katila T. Milk and serum progesterone levels in mares after ovulation.. Acta Vet Scand 1990;31(4):441-4.
          pmc: PMC8133153pubmed: 2099621doi: 10.1186/bf03547526google scholar: lookup
        21. Koskinen E, Huhtinen M, Katila T. Serum progesterone levels in mares in winter and during transitional periods.. Acta Vet Scand 1996;37(4):409-14.
          pmc: PMC8064015pubmed: 9050273doi: 10.1186/bf03548080google scholar: lookup
        22. Neely DP, Hughes JP, Stabenfeldt GH, Evans JW. The influence of intrauterine saline infusion on luteal function and cyclical activity in the mare.. J Reprod Fertil Suppl 1975 Oct;(23):235-9.
          pubmed: 1060784
        23. Neely DP, Kindahl H, Stabenfeldt GH, Edqvist LE, Hughes JP. Prostaglandin release patterns in the mare: physiological, pathophysiological, and therapeutic responses.. J Reprod Fertil Suppl 1979;(27):181-9.
          pubmed: 289787
        24. Hughes JP, Stabenfeldt GH, Kindahl H, Kennedy PC, Edqvist LE, Neely DP, Schalm OW. Pyometra in the mare.. J Reprod Fertil Suppl 1979;(27):321-9.
          pubmed: 289805
        25. Stabenfeldt GH, Kindahl H, Hughes JP, Neely DP, Liu I, Pascoe D. Control of luteolysis in the mare.. Acta Vet Scand Suppl 1981;77:159-70.
          pubmed: 6946691
        26. Kindahl H, Knudsen O, Madej A, Edqvist LE. Progesterone, prostaglandin F-2 alpha, PMSG and oestrone sulphate during early pregnancy in the mare.. J Reprod Fertil Suppl 1982;32:353-9.
          pubmed: 6300390
        27. Kindahl H, Odensvik K, Hansen B, Daels PF. Changes in PGF2alpha secretion during prolonged luteal phase in mares.. J Reprod Fertil Suppl 2000;(56):305-15.
          pubmed: 20681142
        28. Hughes JP, Stabenfeldt GH, Evans JW. The oestrous cycle of the mare.. J Reprod Fertil Suppl 1975 Oct;(23):161-6.
          pubmed: 1060771
        29. Stabenfeldt GH, Hughes JP, Evans JW, Neely DP. Spontaneous prolongation of luteal activity in the mare.. Equine Vet J 1974 Oct;6(4):158-63.
          pubmed: 4473339doi: 10.1111/j.2042-3306.1974.tb03952.xgoogle scholar: lookup
        30. Betteridge KJ, Renard A, Geoff AK. Uterine prostaglandin release relative to embryo collection, transfer procedure and maintenance of the corpus luteum. Equine Vet J 1985. pp. 25–33.
        31. Hofferer S, Duchamp G, Palmer E. Ovarian response in mares to prolonged treatment with exogenous equine pituitary gonadotrophins.. J Reprod Fertil Suppl 1991;44:341-9.
          pubmed: 1795277
        32. Ginther OJ. Prolonged luteal activity in mares--a semantic quagmire.. Equine Vet J 1990 May;22(3):152-6.
          pubmed: 2193807doi: 10.1111/j.2042-3306.1990.tb04235.xgoogle scholar: lookup
        33. Henry JP, Coryn M, Spincemaille J, Vandeplassche M. Prolonged luteal activity in the mare. Zuchthyg 1981;16:145–153.
        34. Fortune JE. Ovarian follicular growth and development in mammals.. Biol Reprod 1994 Feb;50(2):225-32.
          doi: 10.1095/biolreprod50.2.225pubmed: 8142540google scholar: lookup
        35. Evans MJ, Irvine CH. Serum concentrations of FSH, LH and progesterone during the oestrous cycle and early pregnancy in the mare.. J Reprod Fertil Suppl 1975 Oct;(23):193-200.
          pubmed: 1060778
        36. Pierson RA, Ginther OJ. Follicular population dynamics during the estrous cycle of the mare. Anim Reprod Sci 1987;14:219–231.
          doi: 10.1016/0378-4320(87)90085-6google scholar: lookup
        37. Barbacini S, Zavaglia G, Marchi V, Necchi D. Retrospective study on the efficacy of hCG in an equine artificial semination programme using frozen semen. Equine Vet Ed 2000;12:312–317.
        38. Squires EL, Barbacini S, Neechi D, Reger HP, Bruemmer JE. Simplified strategy for insemination of mares with frozen semen. 49th Annual Convention of the American Association of Equine Practitioners: 2003; New Orleans, Louisiana. International Veterinary Information Service, Ithaca, New York, USA.
        39. Bour B, Palmer E, Driancourt MA. Stimulation of ovarian activity in the pony mare during winter anoestrus. In: Ellendorff F, Elsaesser F, editor. Endocrine Causes of Seasonal and Lactational Anestrus in Farm Animals. Boston: Martinus Nijhoff Publishers; 1985. pp. 85–97.

        Citations

        This article has been cited 1 times.
        1. Aurich C, Kaps M. Suppression of reproductive behaviour and gonadal function in female horses-An update. Reprod Domest Anim 2022 Sep;57 Suppl 4(Suppl 4):4-12.
          doi: 10.1111/rda.14129pubmed: 35467049google scholar: lookup
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