Progesterone concentration and ovascan reading during the estrous cycle in arabian mares

Fathalla, M.; Younis, Laith Sofian; Jawad, Noorulhuda

doi:10.1016/s0737-0806(88)80062-5

Cited by 5 publications

(3 citation statements)

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“…13 The decline in VEI in response to the changing ionic balance of vaginal and cervical mucus would suggest that a change in reproductive hormones had occurred, which typically precedes changes in VEI during the normal estrous cycle and pregnancy in other species. 6,7,12,17 Nevertheless no characteristic changes in fecal estrogens or progestagens as measured with the steroid hormone assays and respective antibodies used in this study were noted. Our calibration of the Ovatest probe using dilutions of NaCl to test conductivity showed that an increase in NaCl in solution decreased VEI (694.7 Ϯ 1.5 RU in no NaCl to 24.7 Ϯ 0.3 RU in 1M NaCl).…”

Section: Resultsmentioning

confidence: 65%

“…6,7,10 The principle behind VEI measurements is that a change in the ionic balance of vaginal and cervical mucus occurs in response to changes in reproductive hormones such as estradiol and progesterone. Studies in cattle have shown that fluids within the vagina have high electrical resistance in the luteal phase and that this resistance decreases during the follicular phase.…”

Section: Introductionmentioning

confidence: 99%

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The Relationship Between Vaginal Electrical Impedence and Hormone Profiles During Pregnancy and Parturition of a White Rhinoceros (Ceratotherium Simum Simum)

Bowers

Gandy²,

Paul³

et al. 2005

Journal of Zoo and Wildlife Medicine

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In this study, an attempt was made to use vaginal electrical impedance to predict calving in a female white rhinoceros (Ceratotherium simum simum) and to determine the relationship between vaginal electrical impedance and hormonal profiles during pregnancy. The principle behind vaginal electrical impedance is that a change in the ionic balance of vaginal and cervical mucus occurs in response to changes in reproductive hormones. Three times weekly vaginal electrical impedance readings and fecal samples were collected from midgestation to calving (a 6-mo period). The extracted fecal samples were analyzed for immunoreactive estrogens, progestagens, and corticoids by RIA. Vaginal electrical impedance readings did not decrease before calving but remained consistent throughout the last 140 days of pregnancy. Fecal progestagens in the white rhinoceros decreased between day 17 and day 1 before calving, whereas estrogens increased between 4 and 2 mo before calving, with an additional increase occurring 1 mo before calving. Fecal corticoids increased 5 mo before calving, slowly declined, and increased again within 3 wk before calving. A decline in vaginal electrical impedance was noted 168 days before calving and remained at low levels for 4 wk. At the time of this decrease, the female became aggressive toward the male and began lactating. Fecal progestagens and estrogens did not change during this time; however, fecal corticoids increased as vaginal electrical impedance readings returned to normal along with her behavior and cessation of lactation. In summary, the use of vaginal electrical impedance could not predict parturition in the white rhinoceros. However, an anomaly occurred during pregnancy that was supported by vaginal electrical impedance readings, a change in female behavior, premature lactation, and a subsequent increase in fecal corticoids. The etiology of this physiological anomaly is unknown, yet it did not compromise pregnancy.

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Section: Resultsmentioning

confidence: 65%

Section: Introductionmentioning

confidence: 99%

The Relationship Between Vaginal Electrical Impedence and Hormone Profiles During Pregnancy and Parturition of a White Rhinoceros (Ceratotherium Simum Simum)

Bowers

Gandy²,

Paul³

et al. 2005

Journal of Zoo and Wildlife Medicine

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“…The duration of the estrogenic phase in horses does not allow to predict the exact moment of ovulation [14], and follicle growth monitoring is required for ovulation assessment [3,15]. Therefore, ovulationinducing agents are investigated aiming to increase both artificial insemination (AI) and embryo transfer efficiencies [3,27,29].…”

Section: Introductionmentioning

confidence: 99%

Induction of Ovulation in Mangalarga Marchador Mares by hCG or GnRH

Ferreira-Silva¹,

Nascimento²,

Moura³

et al. 2018

Acta Scientiae. Vet.

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Background: Induction of ovulation is a key procedure for horse assisted reproduction technologies, such as for artificial insemination (AI) and embryo transfer. The application of hCG remains as the primary ovulation-inducing agent for horse assisted reproduction, but alternatives are in demand to avoid its adverse effects, such as loss of ovulation-inducing efficiency over multiple applications by hCC-antibody production. Despite reports on alternative ovulation-inducing agents, pair-wise comparisons of such agents under similar conditions have been limited. Under such scenario, the work was aimed to determine the efficiency of both hCG and Buserelin at inducing ovulation in Mangalarga Marchador mares raised in the Northeast of Brazil under an AI program.Materials, Methods & Results: Mares were initially selected based on their reproductive performance, the absence of clinical-reproductive alterations and adequate body condition score. Mares in diestrus were randomly distributed in three experimental conditions, received 5 mg of Dinoprost and were monitored daily for estrus detection. After estrus detection, ovaries were monitored by ultrasonography, in 12-h intervals, until the follicle reached 35 mm. At this time-point, ovulation was induced with 0.042 mg of Buserelin endovenously, with 3,000 IU hCG by an intramuscular shot, and control mares received 2 mL of saline solution, also by an intramuscular shot. Both hCG and Buserelin displayed similar efficiencies (P > 0.05) for induction of ovulation and that both agents were effective (P < 0.05) for such purpose, since greater percentages (P < 0.05) of induction on mares treated from those of the control. Moreover, the total number of ovulations in mares treated at the end of the experiment was not different (P > 0.05) from those found in the Control. All ovulations occurred within a 72-h period after treatment. It can be observed that in mares treated with hCG or Buserelin, ovulations occurred both in more mares (P < 0.05) and at earlier time-points than mares from the control. It is also possible to note that pregnancy was not different (P > 0.05) between hCG and Buserelin groups, and that pregnancy of mares treated with ovulation-inducing factors was similar to the control.Discussion: The majority of ovulations in mares occurred within initial 48-h after treatment for both hCG and GnRH, suggesting a similar potential for horse assisted reproduction. Both hCG and Buserelin are two commonly used agents for induction of ovulation in mares. As described here, the majority of ovulations occurred within initial 48-h after treatment, a fact which can be attributed to hCG and GnRH activity, since it can happen in intervals from 36 to 48-h after treatment. Pregnancy rates did not differ among groups. These results are under the working hypothesis that hCG and Buserelin would display similar efficiencies on pregnancy rates. Despite the understanding of hCG activity on induction of ovulation due to its high specificity toward LH receptors and results from a direct effect on diminishing estradiol concentration, increasing LH, and further inducing ovulation within 48-h after treatment. In contrast, Buserelin has a similar functional property but acts upon LH synthesis and its release. In conclusion, ovulation in mares can be induced with both hCG and Buserelin, and both ovulation-inducing agents do not affect pregnancy rates.Keywords: gonadotropin, releasing factor, ovary, follicle, corpus luteum.

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Ovarian follicular dynamics and duration of estrus and diestrus in Arabian vs. Quarter Horse mares

Dimmick

Giménez

Schlager

1993

Animal Reproduction Science

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Progesterone concentration and ovascan reading during the estrous cycle in arabian mares

Cited by 5 publications

References 4 publications

The Relationship Between Vaginal Electrical Impedence and Hormone Profiles During Pregnancy and Parturition of a White Rhinoceros (Ceratotherium Simum Simum)

The Relationship Between Vaginal Electrical Impedence and Hormone Profiles During Pregnancy and Parturition of a White Rhinoceros (Ceratotherium Simum Simum)

Induction of Ovulation in Mangalarga Marchador Mares by hCG or GnRH

Ovarian follicular dynamics and duration of estrus and diestrus in Arabian vs. Quarter Horse mares

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