Persistent Link:
http://hdl.handle.net/10150/348035
Title:
Plasma progesterone and cortisol in postpartum beef heifers
Author:
Young, William McFerrin
Issue Date:
1976
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The object of this investigation was to measure the changes in plasma corticoids and progesterone, at two different levels of energy intake during the postpartum period in beef heifers and to assess their relationship to breeding efficiency. Blood samples were taken using a tail bleeding method from 26 first calf crossbred heifers within 24 hours postpartum. Sampling was continued twice weekly until each animal was diagnosed pregnant. Plasma samples were analyzed for progesterone and corticoids using competitive binding techniques. Progesterone levels increased from .5 ng/ml postpartum to 3.7 ng/ml following first ovulation. These levels remained high if conception occurred (5.0 + ng/ml) or returned to minimum levels for repeat estrous cycle. Due to the necessary manipulation of the animals, postpartum plasma levels of corticoids fluctuated widely (10 ng/ml to 70 ng/ml) for each animal. Corticoids means were lower during the postpartum anestrum than during subsequent estrous cycles. No significant correlations were found between plasma corticoids and progesterone concentrations. Providing more than NRC recommended energy intake had no influence on breeding efficiency.
Type:
text; Thesis-Reproduction (electronic)
Keywords:
Progesterone.; Adrenocortical hormones.; Postpartum.
Degree Name:
M.S.
Degree Level:
masters
Degree Program:
Animal Science; Graduate College
Degree Grantor:
University of Arizona

Full metadata record

DC FieldValue Language
dc.language.isoen_USen
dc.titlePlasma progesterone and cortisol in postpartum beef heifersen
dc.creatorYoung, William McFerrinen
dc.contributor.authorYoung, William McFerrinen
dc.date.issued1976en
dc.publisherThe University of Arizona.en
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en
dc.description.abstractThe object of this investigation was to measure the changes in plasma corticoids and progesterone, at two different levels of energy intake during the postpartum period in beef heifers and to assess their relationship to breeding efficiency. Blood samples were taken using a tail bleeding method from 26 first calf crossbred heifers within 24 hours postpartum. Sampling was continued twice weekly until each animal was diagnosed pregnant. Plasma samples were analyzed for progesterone and corticoids using competitive binding techniques. Progesterone levels increased from .5 ng/ml postpartum to 3.7 ng/ml following first ovulation. These levels remained high if conception occurred (5.0 + ng/ml) or returned to minimum levels for repeat estrous cycle. Due to the necessary manipulation of the animals, postpartum plasma levels of corticoids fluctuated widely (10 ng/ml to 70 ng/ml) for each animal. Corticoids means were lower during the postpartum anestrum than during subsequent estrous cycles. No significant correlations were found between plasma corticoids and progesterone concentrations. Providing more than NRC recommended energy intake had no influence on breeding efficiency.en
dc.description.noteThis item was digitized from a paper original and/or a microfilm copy. If you need higher-resolution images for any content in this item, please contact us at repository@u.library.arizona.edu.en
dc.typetexten
dc.typeThesis-Reproduction (electronic)en
dc.subjectProgesterone.en
dc.subjectAdrenocortical hormones.en
dc.subjectPostpartum.en
thesis.degree.nameM.S.en
thesis.degree.levelmastersen
thesis.degree.disciplineAnimal Scienceen
thesis.degree.disciplineGraduate Collegeen
thesis.degree.grantorUniversity of Arizonaen
dc.identifier.oclc701940196en
dc.identifier.bibrecord.b64850456en
dc.identifier.callnumberE9791 1976 456en
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