Ovarian follicles, ovulations and progesterone concentrations in aged versus young mares

Vanderwall, Dirk K.; Woods, G.L.; Freeman, D.A.; Weber, J.A.; Rock, R.W.; Tester, D.F.

doi:10.1016/0093-691x(93)90338-6

Cited by 14 publications

(13 citation statements)

References 19 publications

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“…Aging in mares affects the development of the dominant follicle. Moreover, higher postovulatory plasma progesterone concentrations in young vs. aged mares have been previously reported [ 25 , 26 ]. Although we used hCG treatment for ovulation induction, we did not establish the correlation between that treatment and progesterone concentrations.…”

Section: Discussionmentioning

confidence: 94%

Assessment of Age Effects on Ovarian Hemodynamics Using Doppler Ultrasound and Progesterone Concentrations in Cycling Spanish Purebred Mares

Requena

Campos

Marín

et al. 2021

Animals

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In equine reproduction, accurate and timely detection of the moment of ovulation is of great importance. Power Doppler ultrasound technology is a non-invasive method that enables to assess the morpho-echogenic features and blood flow changes during the estral cycle in mares. The objective of the present study was to evaluate the influence of age on ultrasonographic parameters (follicular diameter, follicular blood flow—FBF, corpus luteum (CL) area and corpus luteum blood flow—CLBF) and blood plasma progesterone concentrations in cycling Spanish Purebred mares (15 less than 8 years old and 15 equal o higher than 8 years old). The ultrasound images obtained were analyzed with the Image Colour Summarizer software, which allows the quantification of the pixels of each image. Young mares had significantly higher FBF, CLBF and plasma progesterone levels. Moreover, linear regression analysis showed that blood progesterone levels could be predicted in both groups from CLBF with moderate precision and accuracy. In conclusion, Power Doppler was useful to assess ovarian hemodynamics. Our results support that age is a factor that significantly influences FBF and CLBF as well as blood progesterone concentration in mares. More studies would be needed to develop high precision and accuracy predictive models of blood progesterone concentration from CLBF measured by Power Doppler.

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Section: Discussionmentioning

confidence: 94%

Assessment of Age Effects on Ovarian Hemodynamics Using Doppler Ultrasound and Progesterone Concentrations in Cycling Spanish Purebred Mares

Requena

Campos

Marín

et al. 2021

Animals

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“…It corresponds, however, to ovarian dysregulation and final reduction of the oocyte pool, with a decrease starting during fetal period, and gradually after puberty. Such a biological process has also been described in horses [ 88 , 89 ]. Indeed, it has been estimated that mares reach ovarian senescence on average at 25 years old [ 20 ].…”

Section: Comparative Anatomical Physiological and Pathological Aspects Of Reproduction In Mares And Womenmentioning

confidence: 99%

“…Indeed, it has been estimated that mares reach ovarian senescence on average at 25 years old [ 20 ]. Moreover, around 17% of mares older than 20 do not ovulate any more [ 88 , 89 ]. In non-human mammalian species that have been studied, only mares seem to be affected by this process, partly because of the prolonged lifespan in this species.…”

Section: Comparative Anatomical Physiological and Pathological Aspects Of Reproduction In Mares And Womenmentioning

confidence: 99%

The Mare: A Pertinent Model for Human Assisted Reproductive Technologies?

Benammar

Derisoud

Vialard

et al. 2021

Animals

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Although there are large differences between horses and humans for reproductive anatomy, follicular dynamics, mono-ovulation, and embryo development kinetics until the blastocyst stage are similar. In contrast to humans, however, horses are seasonal animals and do not have a menstrual cycle. Moreover, horse implantation takes place 30 days later than in humans. In terms of artificial reproduction techniques (ART), oocytes are generally matured in vitro in horses because ovarian stimulation remains inefficient. This allows the collection of oocytes without hormonal treatments. In humans, in vivo matured oocytes are collected after ovarian stimulation. Subsequently, only intra-cytoplasmic sperm injection (ICSI) is performed in horses to produce embryos, whereas both in vitro fertilization and ICSI are applied in humans. Embryos are transferred only as blastocysts in horses. In contrast, four cells to blastocyst stage embryos are transferred in humans. Embryo and oocyte cryopreservation has been mastered in humans, but not completely in horses. Finally, both species share infertility concerns due to ageing and obesity. Thus, reciprocal knowledge could be gained through the comparative study of ART and infertility treatments both in woman and mare, even though the horse could not be used as a single model for human ART.

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“…5 Mares over 25 years of age may cease cycling altogether. There is a delayed entry into the ovulatory season, longer follicular phase (estrus), and fewer ovulations per year.…”

Section: Cycle Irregularities Associated With Agingmentioning

confidence: 99%

Irregularities of the Estrous Cycle and Ovulation in Mares (Including Seasonal Transition)

Hinrichs¹

2007

Current Therapy in Large Animal Theriogenology

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Ovarian follicles, ovulations and progesterone concentrations in aged versus young mares

Cited by 14 publications

References 19 publications

Assessment of Age Effects on Ovarian Hemodynamics Using Doppler Ultrasound and Progesterone Concentrations in Cycling Spanish Purebred Mares

Assessment of Age Effects on Ovarian Hemodynamics Using Doppler Ultrasound and Progesterone Concentrations in Cycling Spanish Purebred Mares

The Mare: A Pertinent Model for Human Assisted Reproductive Technologies?

Irregularities of the Estrous Cycle and Ovulation in Mares (Including Seasonal Transition)

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