Temporal relationships and repeatability of follicle diameters and hormone concentrations within individuals in mares.
Abstract: Data were collected daily from 23 mares during two consecutive interovulatory intervals (IOIs). Several significant (p < 0.05) new observations on temporal relationships were made. The FSH increase that begins before ovulation temporarily plateaued on the day of discharge of follicular fluid into the peritoneal cavity in association with ovulation. During the declining portion of the pre-ovulatory oestradiol surge, an abrupt reduction in the rate of decrease occurred in synchrony with the peak of the LH surge and is consistent with a negative effect of LH on oestradiol. Repeatability within mares was based on the following positive and significant correlations between the two IOIs: (i) length of the interval between ovulations and between ovulation and the beginning of follicle deviation; (ii) diameter of the pre-ovulatory follicle on days -3 to -1; (iii) number of follicles in diameter classes of 2-5 mm (correlation for 22/23 days of the IOI), 5.1-10 mm (18/23 days), 10.1-15 mm (12/23 days) and 15.1-20 mm (12/23 days) and (iv) concentrations of FSH (18/23 days) and LH (22/23 days). The greatest repeatability for the follicle-diameter classes occurred in the 2-5 mm class, and thereafter the repeatability progressively decreased as the diameters for the classes increased. Results demonstrated measurable repeatability within mares for several end points between consecutive IOIs.
Publication Date: 2008-10-15 PubMed ID: 18954382DOI: 10.1111/j.1439-0531.2007.01003.xGoogle Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research observes the relationship between follicle diameters and hormone concentrations in mares over two consecutive interovulatory intervals. They noted significant new findings regarding the timings and patterns, including the impact of certain hormones on others, and found consistent patterns within individual mares across the intervals.
Study Methods
- The research team collected data daily from 23 mares over two consecutive interovulatory intervals (IOIs).
- They observed the diameters of follicles and the levels of various hormones including Follicle stimulating hormone (FSH) and Luteinizing hormone (LH).
New Temporal Observations
- Their observations showed that the increase in FSH, which usually starts before ovulation, briefly levels off when the follicular fluid is discharged into the peritoneal cavity during ovulation.
- As the pre-ovulatory oestradiol (a form of estrogen) surge started to decline, the researchers noticed a sudden decrease in its rate of decline, occurring simultaneously with the peak of the LH surge. This pattern suggests that LH might have a negative effect on oestradiol.
Repeatability within Mares
- The study showed significant and positive correlation within individual mares over the two IOIs in several areas, including the interval length between ovulations and from ovulation to the start of follicle deviation, the diameter of the pre-ovulatory follicle, and the concentrations of FSH and LH.
- The number of follicles in specific size categories also showed a significant correlation across 22/23 days of the IOI for follicles sized 2-5 mm, 18/23 days for 5.1-10 mm, and 12/23 days for follicles sized 10.1-15 mm and 15.1-20 mm.
- Repeatability, or consistency of measurement, was best amongst the 2-5 mm follicle diameter group. The greater the follicle diameters, the less repeatability the researchers observed.
Conclusion
- The study was able to demonstrate measurable repeatability in several measurements within mares across consecutive IOIs. This understanding of the predictable nature of these biological processes can help in the management and care of mares.
Cite This Article
APA
Jacob JC, Gastal EL, Gastal MO, Carvalho GR, Beg MA, Ginther OJ.
(2008).
Temporal relationships and repeatability of follicle diameters and hormone concentrations within individuals in mares.
Reprod Domest Anim, 44(1), 92-99.
https://doi.org/10.1111/j.1439-0531.2007.01003.x Publication
Researcher Affiliations
- Eutheria Foundation, Cross Plains, WI, USA.
MeSH Terms
- Animals
- Estradiol / blood
- Female
- Follicle Stimulating Hormone / blood
- Hormones / blood
- Horses / anatomy & histology
- Horses / blood
- Luteinizing Hormone / blood
- Ovarian Follicle / anatomy & histology
- Ovulation / blood
- Progesterone / blood
- Reproducibility of Results
- Time Factors
Citations
This article has been cited 3 times.- 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).
- Vaiarelli A, Cimadomo D, Trabucco E, Vallefuoco R, Buffo L, Dusi L, Fiorini F, Barnocchi N, Bulletti FM, Rienzi L, Ubaldi FM. Double Stimulation in the Same Ovarian Cycle (DuoStim) to Maximize the Number of Oocytes Retrieved From Poor Prognosis Patients: A Multicenter Experience and SWOT Analysis.. Front Endocrinol (Lausanne) 2018;9:317.
- Newcombe JR, Cuervo-Arango J. Growth rate of ovulatory follicles during the first ovulatory oestrus (after seasonal anoestrus) and subsequent oestrous period in Irish Draught mares.. Ir Vet J 2013 Mar 12;66(1):4.
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