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Molecular reproduction and development2022; 89(2); 113-124; doi: 10.1002/mrd.23552

Dominant follicle and gonadotropin dynamics before ovulation in postpartum lactating mares.

Abstract: The aim of this study was to compare the dominant follicle (DF) and gonadotropin dynamics for 9 days before ovulation in postpartum lactating (PP Lactating) versus non-postpartum cycling (N-PP Cycling) mares. Every PP Lactating mare on the day of parturition was paired with a N-PP Cycling mare, and the data analyses considered the partum-ovulation interval (POI) and the postpartum interovulatory interval (PPIOI) in PP Lactating mares and two interovulatory intervals in N-PP Cycling mares. The results of the present study revealed several novel and unique aspects of DF development and FSH and LH dynamics before ovulation in PP Lactating mares when compared with N-PP Cycling mares. The most remarkable differences between both groups of mares were the following: (1) a shorter interval to ovulation in PP Lactating mares during the foal heat (POI ≤22 days) compared with all other intervals; (2) a larger DF in PP Lactating mares, and an earlier day of DF at maximum diameter during the foal heat; and (3) lower gonadotropin levels in PP Lactating mares. Regarding the particularities, PP Lactating mares had lower LH levels during the POI than the PPIOI, demonstrating a strong partum effect; spring-foaled mares had longer POIs, larger DF diameters, and lower LH levels; and lower body condition scores and higher body-weight loss led to longer POIs and smaller DF diameters in PP Lactating mares. This study contributes to a broad understanding of ovarian function in the postpartum mare.
© 2022 Wiley Periodicals LLC.
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Publication Date: 2022-01-09 PubMed ID: 35001447DOI: 10.1002/mrd.23552Google Scholar: Lookup
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  • Journal Article
  • Research Support
  • Non-U.S. Gov't

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 compares ovarian and hormonal activities leading up to ovulation in mares that have given birth and are lactating, with those in mares that haven’t recently given birth or are not lactating. The results reveal differences in the development of dominant follicles and follicle stimulating and luteinizing hormone levels.

Objective of the Study

  • The goal of the research was to examine how the dynamics of the dominant follicle, which holds the egg that will be released during ovulation, as well as the dynamics of two essential reproductive hormones – follicle stimulating hormone (FSH) and luteinizing hormone (LH) – differ in the period leading up to ovulation between postpartum lactating (recently mothered and currently breastfeeding) mares and those mares that are not postpartum or lactating.

Research Methodology

  • The researchers paired each postpartum lactating mare with a non-postpartum cycling mare. They studied these pairs over a period of 9 days leading up to ovulation.
  • The two main variables considered were the period from parturition (childbirth) to ovulation (POI) and the interovulatory period following parturition (PPIOI) within the postpartum lactating mares. In the case of the non-postpartum cycling mares, two ovulation intervals were taken into account.

Findings

  • The dominant follicle development, and the levels of FSH and LH, showed significant differences before ovulation in lactating mares that had recently given birth compared with mares that were not postpartum or lactating.
  • The interval from childbirth to the first ovulation (known as “foal heat”) was shorter in postpartum lactating mares with the POI being equal to or less than 22 days.
  • The dominant follicle in postpartum lactating mares was larger, and these mares also experienced maximum dominant follicle size earlier during the “foal heat” phase.
  • Postpartum lactating mares showed lower levels of the reproductive hormones, FSH and LH, compared to non-postpartum, non-lactating mares.
  • Within the specific case of postpartum lactating mares, LH levels were lower during the period from childbirth to ovulation than they were in the interovulatory period after that, signifying a strong effect on ovulation resulting from childbirth.
  • The body condition and weight loss of the mares also had an influence. Lower body scores and higher weight loss were associated with longer periods from childbirth to ovulation and smaller dominant follicle sizes.

Significance of the Study

  • The findings from this study provide greater insight into how ovulation functions in mares after giving birth, particularly while they are still lactating. This understanding can have direct implications for breeding horses and can facilitate more successful and efficient breeding practices.

Cite This Article

APA
Gastal MO, Pastorello M, Godoi DB, Gastal EL. (2022). Dominant follicle and gonadotropin dynamics before ovulation in postpartum lactating mares. Mol Reprod Dev, 89(2), 113-124. https://doi.org/10.1002/mrd.23552

Publication

Molecular reproduction and development
ISSN: 1098-2795
NlmUniqueID: 8903333
Country: United States
Language: English
Volume: 89
Issue: 2
Pages: 113-124

Researcher Affiliations

Gastal, Melba O
  • Animal Science, School of Agricultural Sciences, Southern Illinois University, Carbondale, Illinois, USA.
  • Department of Animal Science, Federal University of Viçosa, Viçosa, Brazil.
Pastorello, Marilia
  • Animal Science, School of Agricultural Sciences, Southern Illinois University, Carbondale, Illinois, USA.
Godoi, Daniel B
  • Department of Veterinary, Federal University of Viçosa, Viçosa, Brazil.
Gastal, Eduardo L
  • Animal Science, School of Agricultural Sciences, Southern Illinois University, Carbondale, Illinois, USA.
  • Department of Veterinary, Federal University of Viçosa, Viçosa, Brazil.

MeSH Terms

  • Animals
  • Female
  • Follicle Stimulating Hormone
  • Gonadotropins
  • Horses
  • Humans
  • Lactation
  • Ovarian Follicle
  • Ovulation
  • Postpartum Period

References

This article includes 44 references
  1. Aurich C, Aurich JE, Parvizi N. Opioidergic inhibition of luteinising hormone and prolactin release changes during pregnancy in pony mares. Journal of Endocrinology 169, 511-518.
  2. Blanchard TL, Thompson JA, Brinsko SP, Stich KL, Wendt KM, Varner DD, Rigby SL. Mating mares on foal heat: a five-year retrospective study. Proceedings of the annual convention of the American Association of Equine Practitioners 50, 525-530.
  3. Blanchard TL, Thompson JA, Love CC, Brinsko SP, Ramsey J, O'Meara A, Varner DD. Influence of day of postpartum breeding on pregnancy rate, pregnancy loss rate, and foaling rate in Thoroughbred mares. Theriogenology 77, 1290-1296.
  4. Camillo F, Marmorini P, Romagnoli S, Vannozzi I, Bagliacca M. Fertility at the first post partum estrous compared with fertility at the following estrous cycles in foaling mares and with fertility in nonfoaling mares. Journal of Equine Veterinary Science 17, 612-616.
  5. Chevalier-Clément F. Pregnancy loss in the mare. Animal Reproduction Science 20, 231-244.
  6. Deichsel K, Aurich J. Lactation and lactational effects on metabolism and reproduction in the horse mare. Livestock Production Science 98, 25-30.
  7. Deichsel K, Aurich J, Parvizi N, Bruckmaier RM, Aurich C. LH and IGF-1 release during oestrus and early luteal phase in lactating and non-lactating horse mares. Animal Reproduction Science 91, 97-106.
  8. Gastal EL. Recent advances and new concepts on follicle and endocrine dynamics during the equine periovulatory period. Animal Reproduction 6, 144-158.
  9. Gastal EL, Bergfelt DR, Nogueira GP, Gastal MO, Ginther OJ. Role of luteinizing hormone in follicle deviation based on manipulating progesterone concentrations in mares. Biology of Reproduction 61, 1492-1498.
  10. Gastal EL, Gastal MO, Beg MA, Ginther OJ. Interrelationships among follicles during the common-growth phase of a follicular wave and capacity of individual follicles for dominance in mares. Reproduction 128, 417-422.
  11. Gastal EL, Gastal MO, Bergfelt DR, Ginther OJ. Role of diameter differences among follicles in selection of a future dominant follicle in mares. Biology of Reproduction 57, 1320-1327.
  12. Gastal EL, Gastal MO, Donadeu FX, Acosta TJ, Beg MA, Ginther OJ. Temporal relationships among LH, estradiol, and follicle vascularization preceding the first compared with later ovulations during the year in mares. Animal Reproduction Science 102, 314-321.
  13. Gastal EL, Gastal MO, Ginther OJ. The suitability of echotexture characteristics of the follicular wall for identifying the optimal breeding day in mares. Theriogenology 50, 1025-1038.
  14. Gastal EL, Gastal MO, Nogueira GP, Bergfelt DR, Ginther OJ. Temporal interrelationships among luteolysis, FSH and LH concentrations and follicle deviation in mares. Theriogenology 53, 925-940.
  15. Gastal EL, Gastal MO, Wischral A, Davis J. The equine model to study the influence of obesity and insulin resistance in human ovarian function. Acta Scientiae Veterinariae 39, s57-s70.
  16. Gastal EL, Neves AP, Mattos RC, Petrucci BPL, Gastal MO, Ginther OJ. Miniature ponies: 1. Follicular, luteal and endometrial dynamics during the oestrous cycle. Reproduction, Fertility, and Development 20, 376-385.
  17. Gastal MO, Gastal EL, Spinelli V, Ginther OJ. Relationships between body condition and follicle development in mares. Animal Reproduction 1, 115-121.
  18. Ginther OJ. Reproductive biology of the mare: Basic and applied aspects (2nd ed.). Cross Plains, WI: Equiservices Publishing.
  19. Ginther OJ. Ultrasonic imaging and animal reproduction: Horses, book 2. Cross Plains, WI: Equiservices Publishing.
  20. Ginther OJ. Follicle selection in mares: 90 years from observation to theory. Journal of Equine Veterinary Science 54, 24-31.
  21. Ginther OJ, Baucus KL, Bergfelt DR. Follicular and FSH responses to parturition during the anovulatory season in mares. Theriogenology 41, 613-627.
  22. Ginther OJ, Beg MA, Gastal EL, Gastal MO, Baerwald AR, Pierson RA. Systemic concentrations of hormones during the development of follicular waves in mares and women: a comparative study. Reproduction 130, 379-388.
  23. Ginther OJ, Beg MA, Gastal MO, Gastal EL. Follicle dynamics and selection in mares. Animal Reproduction 11, 45-63.
  24. Ginther OJ, Beg MA, Neves AP, Mattos RC, Petrucci BPL, Gastal MO, Gastal EL. Miniature ponies: 2. Endocrinology of the oestrous cycle. Reproduction, Fertility, and Development 20, 386-390.
  25. Ginther OJ, Gastal EL, Gastal MO, Beg MA. Seasonal influence on equine follicle dynamics. Animal Reproduction 11, 31-44.
  26. Ginther OJ, Gastal EL, Gastal MO, Beg MA. Regulation of circulating gonadotropin by the negative effects of ovarian hormones in mares. Biology of Reproduction 73, 315-323.
  27. Ginther OJ, Gastal EL, Gastal MO, Bergfelt DR, Baerwald AR, Pierson RA. Comparative study of the dynamics of follicular waves in mares and women. Biology of Reproduction 71, 1195-1201.
  28. Ginther OJ, Pierson RA. Regular and irregular characteristics of ovulation and the interovulatory interval in mares. Journal of Equine Veterinary Science 9, 4-12.
  29. Heidler B, Parvizi N, Sauerwein H, Bruckmaier RM, Heintges U, Aurich JE, Aurich C. Effects of lactation on metabolic and reproductive hormones in Lipizzaner mares. Domestic Animal Endocrinology 25, 47-59.
  30. Henneke DR, Potter GD, Kreider JL. Body condition during pregnancy and lactation and reproductive efficiency of mares. Theriogenology 21, 897-909.
  31. Henneke DR, Potter GD, Kreider JL, Yeates BF. Relationship between condition score, physical measurements and body fat percentage in mares. Equine Veterinary Journal 15, 371-372.
  32. Hines KK, Fitzgerald BP, Loy RG. Effect of pulsatile gonadotrophin release on mean serum LH and FSH in peri-parturient mares. Journal of Reproduction and Fertility. Supplement 35, 635-640.
  33. Ishak GM, Bashir ST, Gastal MO, Gastal EL. Pre-ovulatory follicle affects corpus luteum diameter, blood flow, and progesterone production in mares. Animal Reproduction Science 187, 1-12.
  34. Ishak GM, Dutra GA, Gastal GDA, Elcombe ME, Gastal MO, Park SB, Feugang JM, Gastal EL. Deficiency in proliferative, angiogenic, and LH receptors in the follicle wall: implications of season toward the anovulatory condition. Domestic Animal Endocrinology 70, 106382.
  35. Koskinen E. Post-partum ovarian activity in Finnhorse mares with special reference to seasonal effects. Acta Veterinaria Scandinavica 32, 313-318.
  36. Loy RG. Characteristics of postpartum reproduction in mares. Veterinary Clinics of North America: Food Animal Practice 2, 345-359.
  37. Meyers PJ, Bonnett BN, McKee SL. Quantifying the occurrence of early embryonic mortality on three equine breeding farms. Canadian Veterinary Journal 32, 665-672.
  38. Nagy P, Guillaume D, Daels P. Seasonality in mares. Animal Reproduction Science 60-61, 245-262.
  39. Nagy P, Huszenicza G, Juhász J, Kulcsár M, Solti L, Reiczigel J, Abaváry K. Factors influencing ovarian activity and sexual behavior of postpartum mares under farm conditions. Theriogenology 50, 1109-1119.
  40. Palmer E, Driancourt MA. Some interactions of season of foaling, photoperiod and ovarian activity in the equine. Livestock Production Science 10, 197-210.
  41. Sargent GF, Pope NS, Kesler DJ. Postpartum LH profile characteristics, estrus and ovulation: The influence of short-term foal removal. Journal of Equine Veterinary Science 8, 156-160.
  42. Sharma S, Davies Morel MCG, Dhaliwal GS. Factors affecting the incidence of postpartum oestrus, ovarian activity and reproductive performance in Thoroughbred mares bred at foal heat under Indian subtropical conditions. Theriogenology 74, 90-99.
  43. Thompson DL Jr, Johnson L, St. George RL, Garza F Jr. Concentrations of prolactin, luteinizing hormone and follicle stimulating hormone in pituitary and serum of horses: effect of sex, season and reproductive state. Journal of Animal Science 63, 854-860.
  44. Turner DD, Garcia MC, Ginther OJ. Follicular and gonadotropic changes throughout the year in pony mares. American Journal of Veterinary Research 40, 1694-1700.

Citations

This article has been cited 2 times.
  1. Cardona-García M, Jiménez-Escobar C, Ferrer MS, Maldonado-Estrada JG. Follicular Dynamics and Pregnancy Rates during Foal Heat in Colombian Paso Fino Mares Bred under Permanent Grazing. Animals (Basel) 2024 Feb 29;14(5).
    doi: 10.3390/ani14050760pubmed: 38473144google scholar: lookup
  2. Segabinazzi LGTM, Gilbert RO, Ambrosia RL, Bergfelt DR, Samper JC, Peterson EW, French HM. Structural and Functional Dynamics of the Ovary and Uterus during the Estrous Cycle in Donkeys in the Eastern Caribbean. Animals (Basel) 2022 Dec 24;13(1).
    doi: 10.3390/ani13010074pubmed: 36611684google scholar: lookup
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