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Study · Measured the body's own peptide · 2016

5 results

High interindividual and intraindividual variation of oxytocin secretion in estrous mares exposed to stallions, but no significant link to mate preferences.

Käser R, Bruckmaier RM, Thomas S, Sieme H, Wedekind C, Burger D

Theriogenology25 Jul 2016Cited by 1 (Europe PMC)

PMID27587272 (opens in a new tab)DOI10.1016/j.theriogenology.2016.07.017 (opens in a new tab)PepBankPUB-27587272
Publisher pagePubMedAsk about this study
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Summary

The text of this summary is not shown here, because the article license does not allow reuse. Read it at the source (opens in a new tab)

Text rights: Publisher copyright. Results still quote short attributed sentences.

Results from this study5

No result from this study comes from a test of the peptide.

Natural levels measured5

These results measure the body's own peptide. Nobody was given the peptide. They are not evidence about taking it. They are left out of key results, evidence counts and charts.

  1. 01AnimalEndogenous levelOther designOther

    In estrous mares, the body's own oxytocin concentrations were significantly elevated during exposure to a stallion in 20 of 26 trials.

    In plain wordsIn mares in heat, the body's own oxytocin rose when a stallion was present in most trials.

    Peptide
    Oxytocin
    Outcome
    IncreaseOxytocin plasma concentration during stallion exposure
    Study

    horsen = 13

    Estrous mares exposed to stallions
    Comparator
    Before exposure
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health

    Source sentences

    Summary
    In 20 of the 26 trials, oxytocin concentrations were significantly elevated during exposure to the stallion
    2 context sentences
    Summary · context
    We therefore tested if the concentrations of oxytocin and other hormones reveal mate preferences of 13 mares in estrus.
    Summary · context
    Approximately 4.5 hours later, venous blood samples were collected every minute during 30 minutes preceding exposure to one of the two previously used stallions, 6 minutes during exposure, and 30 minutes after exposure back in the mare's box.

    This result measures the body's own Oxytocin. Nobody was given the peptide. It is not evidence about taking it.

  2. 02AnimalEndogenous levelOther designOther

    In estrous mares, the body's own oxytocin rise during stallion exposure showed no significant association with cortisol or estradiol concentrations.

    In plain wordsIn mares in heat, the body's own oxytocin rise was not linked to cortisol or estradiol levels.

    Peptide
    Oxytocin
    Outcome
    No significant changeAssociation of oxytocin with cortisol and estradiol
    Study

    horsen = 13

    Estrous mares exposed to stallions
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health

    Source sentences

    Summary
    without significant associations to cortisol and estradiol concentrations.
    2 context sentences
    Summary · context
    We therefore tested if the concentrations of oxytocin and other hormones reveal mate preferences of 13 mares in estrus.
    Summary · context
    Approximately 4.5 hours later, venous blood samples were collected every minute during 30 minutes preceding exposure to one of the two previously used stallions, 6 minutes during exposure, and 30 minutes after exposure back in the mare's box.

    This result measures the body's own Oxytocin. Nobody was given the peptide. It is not evidence about taking it.

  3. 03AnimalEndogenous levelOther designOther

    In estrous mares, the body's own oxytocin secretion was not significantly associated with mate preference.

    In plain wordsIn mares in heat, the body's own oxytocin levels did not predict which stallion they preferred.

    Peptide
    Oxytocin
    Outcome
    No significant changeAssociation of oxytocin secretion with mate preference
    Study

    horsen = 13

    Estrous mares exposed to stallions
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health

    Source sentences

    Summary
    We found no significant association between oxytocin secretion and preferences in the previous choice situation.
    2 context sentences
    Summary · context
    We therefore tested if the concentrations of oxytocin and other hormones reveal mate preferences of 13 mares in estrus.
    Summary · context
    Approximately 4.5 hours later, venous blood samples were collected every minute during 30 minutes preceding exposure to one of the two previously used stallions, 6 minutes during exposure, and 30 minutes after exposure back in the mare's box.

    This result measures the body's own Oxytocin. Nobody was given the peptide. It is not evidence about taking it.

  4. 04AnimalEndogenous levelOther designOther

    In estrous mares, the body's own oxytocin and cortisol concentrations differed considerably between two cycles within the same mare, unlike estradiol.

    In plain wordsIn mares in heat, the body's own oxytocin levels varied a lot within the same mare between two cycles.

    Peptide
    Oxytocin
    Outcome
    Not applicableRepeatability of oxytocin concentration across two cycles
    Study

    horsen = 13

    Estrous mares exposed to stallions
    Comparator
    Other estrus cycle
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health

    Source sentences

    Summary
    While estradiol concentration showed a high repeatability over the two cycles, we found considerable intraindividual differences in oxytocin and cortisol plasma concentration among the two cycles.
    2 context sentences
    Summary · context
    We therefore tested if the concentrations of oxytocin and other hormones reveal mate preferences of 13 mares in estrus.
    Summary · context
    Approximately 4.5 hours later, venous blood samples were collected every minute during 30 minutes preceding exposure to one of the two previously used stallions, 6 minutes during exposure, and 30 minutes after exposure back in the mare's box.

    This result measures the body's own Oxytocin. Nobody was given the peptide. It is not evidence about taking it.

  5. 05AnimalEndogenous levelOther designOther

    In estrous mares, the body's own oxytocin plasma concentrations were partly lower in mares that ovulated later than expected.

    In plain wordsIn mares in heat, the body's own oxytocin levels were partly lower in mares that ovulated later than expected.

    Peptide
    Oxytocin
    Outcome
    DecreaseOxytocin concentration by time of ovulation
    Study

    horsen = 13

    Estrous mares exposed to stallions
    Comparator
    Mares that ovulated as expected
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health

    Source sentences

    Summary
    Partially, the variation in oxytocin concentrations could be linked to the time of ovulation, with lower oxytocin plasma concentrations in mares which ovulated later than expected.
    2 context sentences
    Summary · context
    We therefore tested if the concentrations of oxytocin and other hormones reveal mate preferences of 13 mares in estrus.
    Summary · context
    Approximately 4.5 hours later, venous blood samples were collected every minute during 30 minutes preceding exposure to one of the two previously used stallions, 6 minutes during exposure, and 30 minutes after exposure back in the mare's box.

    This result measures the body's own Oxytocin. Nobody was given the peptide. It is not evidence about taking it.

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

  1. Version 2Current

    11 Oct 2026, 01:30 UTC

    Study results updated

  2. Version 1

    9 Oct 2026, 02:49 UTC

    First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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