FSH and LH concentrations in periparturient mares.
Abstract: The influence of the ovaries and presence of a foal on periparturient concentrations of FSH and LH were studied in 19 Pony mares. In intact and ovariectomized mares, mean concentrations of FSH fluctuated between 1.1and 9.9 ng/ml on Days -14 to-1 before parturition (Day 0). A surge of FSH occurred in all mares in association with parturition. From Days 1 to 10, the high levels of FSH gradually decreased in the intact group to the minimal concentrations that occur during oestrus, but remained elevated in the ovariectomized mares. There were no significant pre-partum changes in LH in either type of mare. Post-partum changes in LH concentrations increased at a similar rate in ovariectomized and intact mares. The presence of a foal significantly lengthened the interval to first oestrus, depressed LH levels on Days 6--10 and decreased the FSH concentrations as averaged over the 10 days before the first ovulation after parturition.
Publication Date: 1979-01-01 PubMed ID: 289835
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- Journal Article
Summary
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The research examines the changes in concentration levels of two hormones, Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH), in mares around the time of childbirth. The study specifically evaluates the impacts of ovaries and the presence of a newborn foal on these hormone concentrations.
Study Overview
- In this study, researchers investigated the concentration levels of FSH and LH, two key hormones in the reproduction cycle, in 19 Pony mares pre- and post-parturition (childbirth).
- The investigation involved both mares with intact ovaries and mares who had undergone ovariectomy (ovaries removal).
Key Findings
- The study found that FSH levels fluctuated in the days leading up to parturition for both intact and ovariectomized mares, with concentrations ranging from 1.1 to 9.9 ng/ml.
- An FSH surge associated with parturition was observed for all mares. Afterwards, FSH levels began to gradually decrease in the intact group, reaching minimal concentrations associated with oestrus (sexual receptivity). However, FSH levels remained elevated in ovariectomized mares.
- There were no significant changes observed in LH concentrations prior to parturition in either group of mares. After parturition, though, LH concentrations increased at a similar rate for both groups.
- The presence of a newborn foal had observable effects on hormone concentrations and ovulation. It increased the duration between parturition and the first oestrus, reduced LH levels between the 6th and 10th day, and lowered FSH levels as averaged over the 10 days prior to the first post-partum ovulation.
Implications of the Study
- This research enhances our understanding of hormonal regulation during and after the mare’s parturition.
- It suggests that both the state of the ovaries and the presence of a newborn foal play roles in mediating changes in FSH and LH concentrations.
- Such understanding may help to predict fertility cycles better and improve reproduction management strategies in equines.
Cite This Article
APA
Turner DD, Garcia MC, Miller KF, Holtan DW, Ginther OJ.
(1979).
FSH and LH concentrations in periparturient mares.
J Reprod Fertil Suppl(27), 547-553.
Publication
Researcher Affiliations
MeSH Terms
- Animals
- Female
- Follicle Stimulating Hormone / blood
- Horses / blood
- Luteinizing Hormone / blood
- Ovulation
- Postpartum Period
- Pregnancy
- Pregnancy, Animal
Citations
This article has been cited 1 times.- Dhakal P, Tsunoda N, Nambo Y, Taniyama H, Nagaoka K, Watanabe G, Taya K. Circulating activin A during equine gestation and immunolocalization of its receptors system in utero-placental tissues and fetal gonads. J Equine Sci 2021 Jun;32(2):39-48.
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