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dc.contributor.advisorForrest, David
dc.creatorStutts, Kyle Jeffrey
dc.date.accessioned2006-10-30T23:25:10Z
dc.date.available2006-10-30T23:25:10Z
dc.date.created2005-08
dc.date.issued2006-10-30
dc.identifier.urihttp://hdl.handle.net/1969.1/4208
dc.description.abstractTwo experiments tested the efficacy of gonadotropin-releasing hormone (GnRH) or estradiol cypionate (ECP) administration in combination with controlled internal drug release (CIDR) inserts on pregnancy rate to fixed-time artificial insemination (FTAI) in beef heifers. In the first experiment, heifers in the two ECP groups received ECP in conjunction with the CIDR insert. The CIDR insert was removed and PGF was administered on either d 7 or 9. Heifers received ECP 24 h after CIDR removal and were inseminated 30 h after ECP. Heifers in the two GnRH groups received GnRH in conjunction with the CIDR insert. Heifers received PGF on either d 6 or 7, and the CIDR insert was removed on d 7. Heifers were inseminated and received GnRH 48 h after CIDR removal. Pregnancy rates to FTAI were higher for heifers treated with GnRH. Pregnancy rate to FTAI was highest for heifers in the GnRH group that received PGF on d 6 and was lowest for the group that received ECP in combination with a 7-d CIDR insert. In the second experiment, heifers received GnRH in conjunction with the CIDR insert. CIDR inserts were removed and PGF was administered on d 7. Heifers were inseminated 60 h later, with one group receiving GnRH at insemination. Pregnancy rate to FTAI was higher for heifers that received GnRH at insemination. The final experiment tested the efficacy of estradiol 17_ (E17) or GnRH in combination with a CIDR insert on pregnancy rate to FTAI in Brahman cows. Either E17 or GnRH was administered in conjunction with the CIDR insert. CIDR inserts were removed on d 7. Cows in the GnRH group received PGF on d 6 and GnRH at insemination which occurred 48 h after CIDR removal. Cows in the E17 group received PGF on d 7, E17 24 h later, and were inseminated 30 h after E17 administration. Pregnancy rate to FTAI was higher for cows treated with E17. These data indicate acceptable pregnancy rates were obtained when the CIDR insert was combined with either GnRH in beef heifers or with E17 in Brahman cows.en
dc.format.extent552936 bytesen
dc.format.mediumelectronicen
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.publisherTexas A&M University
dc.subjectbeef cattleen
dc.subjectestrous synchronizationen
dc.titleSynchronization of follicular wave emergence, luteal regression, and ovulation for fixed-time artificial insemination in beef cows and heifersen
dc.typeBooken
dc.typeThesisen
thesis.degree.departmentAnimal Scienceen
thesis.degree.disciplinePhysiology of Reproductionen
thesis.degree.grantorTexas A&M Universityen
thesis.degree.nameDoctor of Philosophyen
thesis.degree.levelDoctoralen
dc.contributor.committeeMemberLooney, Charles
dc.contributor.committeeMemberSprott, L. R.
dc.contributor.committeeMemberWikse, Steven
dc.type.genreElectronic Dissertationen
dc.type.materialtexten
dc.format.digitalOriginborn digitalen


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