FREE SHIPPING over $40
OVER 9000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Home / Equine Research Bank / J Vet Med Sci / Analysis of the equine ovarian structure during the first tw...
The Journal of veterinary medical science2015; 77(12); 1599-1603; doi: 10.1292/jvms.14-0539

Analysis of the equine ovarian structure during the first twelve months of life by three-dimensional internal structure microscopy.

Abstract: A three-dimensional internal structure microscopy (3D-ISM) can clarify the anatomical arrangement of internal structures of equine ovaries. In this study, morphological changes of the equine ovary over the first 12 months of life were investigated by 3D-ISM in 59 fillies and by histological analysis in 2 fillies. The weight and volume of the paired ovaries initially decreased from 0 to 1 months to 2 to 3 months of age and then significantly increased at 8 to 12 months of age. The ovulation fossa was first observed around the 3rd month and became evident after the 6th month. The number of follicles with a diameter of ≥10 mm and the diameter of the largest follicle increased gradually after 6 months of age. On a volume basis, the medulla accounted for nearly 90% of the whole ovary at 0 to 1 months of age, but significantly decreased from 2 to 3 months of age. The volume of the cortex increased progressively after birth and reached approximately 60% of the total volume at 8 to 12 months of age. This significant development of the cortex coincided with the increased number and size of large follicles observed from 6 months of age. These results suggest that the development of the cortex plays a role in the maturation of the follicles and the equine ovary undergoes substantial morphological changes postnatally until puberty.
Get Full Text
Publication Date: 2015-07-18 PubMed ID: 26194605PubMed Central: PMC4710715DOI: 10.1292/jvms.14-0539Google 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.
LinkedInCopy
  • 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 the changes in the structure of horse ovaries during the first year of life using a three-dimensional microscope. The findings show that the horse ovary undergoes significant changes and growth during this period, suggesting that the development of the outer layer of the ovary plays a role in the maturation of the ovaries and the eggs within them.

Study Methodology

  • The researchers used a three-dimensional internal structure microscope (3D-ISM), a device that enables a detailed examination of the internal structure of biological samples, to investigate the morphological changes that occurred in the ovaries of young fillies over their first year of life.
  • The team studied a total of 59 fillies, with some undergoing histological analysis, a more detailed technique used to study the microscopic structure of tissues.

Main Findings

  • The weight and volume of the paired ovaries were found to decrease in the first 1-3 months, before significantly increasing between 8 to 12 months.
  • The ovulation fossa, a depression in the ovary where ovulation occurs, became noticeable around the third month and prominent after the sixth month.
  • The number of follicles (structures in the ovaries that mature into eggs) with a diameter of ≥10 mm and the diameter of the largest follicle increased after six months of age.
  • On a volume basis, the medulla (the inner region of the ovary) composed nearly 90% of the ovary at birth, but this proportion decreased significantly by the time the foal was 2 to 3 months old.
  • The volume of the cortex (the outer portion of the ovary) progressively increased after birth, composing about 60% of the total volume at 8 to 12 months of age.
  • The significant development of the cortex coincided with the increased number and size of large follicles observed after 6 months of age.

Conclusion

  • The researchers concluded that the data suggests the development of the cortex plays a significant role in the maturation of the horse’s ovaries and the follicles within them.
  • The study showed that equine ovaries undergo substantial changes postnatally until puberty, possibly allowing for a better understanding of ovarian development, function, and potential reproductive issues in horses.

Cite This Article

APA
Ono M, Akuzawa H, Nambo Y, Hirano Y, Kimura J, Takemoto S, Nakamura S, Yokota H, Himeno R, Higuchi T, Ohtaki T, Tsumagari S. (2015). Analysis of the equine ovarian structure during the first twelve months of life by three-dimensional internal structure microscopy. J Vet Med Sci, 77(12), 1599-1603. https://doi.org/10.1292/jvms.14-0539

Publication

The Journal of veterinary medical science
ISSN: 1347-7439
NlmUniqueID: 9105360
Country: Japan
Language: English
Volume: 77
Issue: 12
Pages: 1599-1603

Researcher Affiliations

Ono, Mamiko
  • Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
Akuzawa, Hiroki
    Nambo, Yasuo
      Hirano, Yuuko
        Kimura, Junpei
          Takemoto, Satoko
            Nakamura, Sakiko
              Yokota, Hideo
                Himeno, Ryutaro
                  Higuchi, Tohru
                    Ohtaki, Tadatoshi
                      Tsumagari, Shigehisa

                        MeSH Terms

                        • Aging
                        • Animals
                        • Female
                        • Horses / growth & development
                        • Imaging, Three-Dimensional / methods
                        • Imaging, Three-Dimensional / veterinary
                        • Microscopy / methods
                        • Microscopy / veterinary
                        • Ovary / anatomy & histology
                        • Ovary / growth & development

                        References

                        This article includes 28 references
                        1. Allen WR. Fetomaternal interactions and influences during equine pregnancy.. Reproduction 2001 Apr;121(4):513-27.
                          doi: 10.1530/rep.0.1210513pubmed: 11277870google scholar: lookup
                        2. Arthur G. H.. An analysis of the reproductive function of mares based on post-mortem examination.. Vet. Rec. 70: 682–686.
                        3. Aurich C. Reproductive cycles of horses.. Anim Reprod Sci 2011 Apr;124(3-4):220-8.
                          doi: 10.1016/j.anireprosci.2011.02.005pubmed: 21377299google scholar: lookup
                        4. Brown-Douglas CG, Firth EC, Parkinson TJ, Fennessy PF. Onset of puberty in pasture-raised Thoroughbreds born in southern hemisphere spring and autumn.. Equine Vet J 2004 Sep;36(6):499-504.
                          doi: 10.2746/0425164044877422pubmed: 15460074google scholar: lookup
                        5. Dyce K. M., Sack W. O., Wensing C. J. G.. The pelvis and reproductive organs of the horse.. pp. 563–585. In: Textbook of Veterinary Anatomy, 4th ed., Saunders, St. Louis.
                        6. ENDERS AC, BUCHANAN GD. The reproductive tract of the female nine-banded armadillo.. Tex Rep Biol Med 1959;17:323-40.
                          pubmed: 13820242
                        7. Ginther O. J.. Reproductive anatomy.. pp. 1–40. In: Reproductive Biology of the Mare: Basic and Applied Aspects, 2nd ed., Equiservices Publishing, Cross Plains.
                        8. Ginther O. J.. Parturition, puerperium and puberty.. pp. 457–498. In: Reproductive Biology of the Mare: Basic and Applied Aspects, 2nd ed., Equiservices Publishing, Cross Plains.
                        9. González-Angulo A, Hernández-Jáuregui P, Márquez-Monter H. Fine structure of gonads of the fetus of the horse (Equus caballus).. Am J Vet Res 1971 Nov;32(11):1665-76.
                          pubmed: 4107761
                        10. González-Angulo A, Hernández-Jáuregui P, Martínez-Zedilo G. Fine structure of the gonads of the horse and its functional implications.. J Reprod Fertil Suppl 1975 Oct;(23):563-7.
                          pubmed: 1060845
                        11. Hay MF, Allen WR. An ultrastructural and histochemical study of the interstitial cells in the gonads of the fetal horse.. J Reprod Fertil Suppl 1975 Oct;(23):557-61.
                          pubmed: 1060844
                        12. Hirano Y, Kimura J, Nambo Y, Yokota H, Nakamura S, Takemoto S, Himeno R, Mishima T, Matsui M, Miyake YI. Population of follicles and luteal structures during the oestrous cycle of mares detected by three-dimensional internal structure microscopy.. Anat Histol Embryol 2009 Jun;38(3):214-8.
                          doi: 10.1111/j.1439-0264.2008.00924.xpubmed: 19469767google scholar: lookup
                        13. Hondo E., Murabayashi H., Hoshiba H., Kitamura N., Yamanouchi K., Nambo Y., Kobayashi T., Kurohmaru M., Yamada J.. Morphological studies on testicular development in the horse.. J. Reprod. Dev. 44: 377–383.
                          doi: 10.1262/jrd.44.377google scholar: lookup
                        14. Kainer R. A.. Reproductive organs of the mare.. pp. 5–19. In: Equine Reproduction. (McKinnon, A. O. and Voss, J. L. eds.), Lea & Febiger, Philadelphia.
                        15. Kimur J, Tsukise A, Yokota H, Nambo Y, Higuchi T. The application of three-dimensional internal structure microscopy in the observation of mare ovary.. Anat Histol Embryol 2001 Oct;30(5):309-12.
                          doi: 10.1046/j.1439-0264.2001.00335.xpubmed: 11688742google scholar: lookup
                        16. Kimura J, Hirano Y, Takemoto S, Nambo Y, Ishinazaka T, Himeno R, Mishima T, Tsumagari S, Yokota H. Three-dimensional reconstruction of the equine ovary.. Anat Histol Embryol 2005 Feb;34(1):48-51.
                          doi: 10.1111/j.1439-0264.2004.00567.xpubmed: 15649227google scholar: lookup
                        17. Kimura J, Kakusho N, Yamazawa K, Hirano Y, Nambo Y, Yokota H, Himeno R. Stereolithographic biomodeling of equine ovary based on 3D serial digitizing device.. J Vet Sci 2009 Jun;10(2):161-3.
                          doi: 10.4142/jvs.2009.10.2.161pmc: PMC2801120pubmed: 19461213google scholar: lookup
                        18. Mlodawska W, Okolski A. Morphological characterization and meiotic competence of oocytes collected from filly ovaries.. Theriogenology 2009 Apr 15;71(7):1046-53.
                          doi: 10.1016/j.theriogenology.2008.11.011pubmed: 19185910google scholar: lookup
                        19. Nogueira GP, Ginther J. Dynamics of follicle populations and gonadotropin concentrations in fillies age two to ten months.. Equine Vet J 2000 Nov;32(6):482-8.
                          doi: 10.2746/042516400777584686pubmed: 11093621google scholar: lookup
                        20. Nogueira GP. Follicle profile and plasma gonadotropin concentration in pubertal female ponies.. Braz J Med Biol Res 2004 Jun;37(6):913-22.
                          doi: 10.1590/S0100-879X2004000600018pubmed: 15264036google scholar: lookup
                        21. Pierson RA, Ginther OJ. Ultrasonic evaluation of the preovulatory follicle in the mare.. Theriogenology 1985 Sep;24(3):359-68.
                          doi: 10.1016/0093-691X(85)90228-6pubmed: 16726090google scholar: lookup
                        22. Stabenfeldt GH, Hughes JP, Evans JW, Geschwind II. Unique aspects of the reproductive cycle of the mare.. J Reprod Fertil Suppl 1975 Oct;(23):155-60.
                          pubmed: 1060770
                        23. Tsunoda N., Machida N., Nagata S., Nagamine N., Nambo Y., Oikawa M., Taniyama H., Watanabe G., Taya K.. A morphometric study of interstitial cells in equine fetal gonads.. J. Reprod. Dev. 42: j91–j95.
                          doi: 10.1262/jrd.96-426j91google scholar: lookup
                        24. Walt ML, Stabenfeldt GH, Hughes JP, Neely DP, Bradbury R. Development of the equine ovary and ovulation fossa.. J Reprod Fertil Suppl 1979;(27):471-7.
                          pubmed: 289826
                        25. Weir B. J., Rowlands I. W.. Functional anatomy of the hystricomorph ovary.. Symp. Zool. Soc. Lond. 34: 303–332.
                        26. 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
                        27. Wesson JA, Ginther OJ. Puberty in the female pony: reproductive behavior, ovulation, and plasma gonadotropin concentrations.. Biol Reprod 1981 Jun;24(5):977-86.
                          doi: 10.1095/biolreprod24.5.977pubmed: 6791718google scholar: lookup
                        28. Witherspoon DM, Talbot RB. Ovulation site in the mare.. J Am Vet Med Assoc 1970 Dec 1;157(11):1452-9.
                          pubmed: 4249600

                        Citations

                        This article has been cited 1 times.
                        1. Alves BG, Alves KA, Gastal GDA, Gastal MO, Figueiredo JR, Gastal EL. Spatial distribution of preantral follicles in the equine ovary. PLoS One 2018;13(6):e0198108.
                          doi: 10.1371/journal.pone.0198108pubmed: 29897931google scholar: lookup
                        Subscribe to our newsletter
                        Join 99,359 horse owners like you who receive our email updates on horse health and nutrition.