VTechWorks staff will be away for the Thanksgiving holiday beginning at noon on Wednesday, November 27, through Friday, November 29. We will resume normal operations on Monday, December 2. Thank you for your patience.
 

The effects of varying the interval from follicular wave emergence to progestin withdrawal on follicular dynamics and the synchrony of estrus in beef cattle

Simple item page
dc.contributor.authorUtt, Matthew Douglasen
dc.contributor.committeechairBeal, Wilfred E.en
dc.contributor.committeememberSaacke, Richard G.en
dc.contributor.committeememberEstienne, Mark J.en
dc.contributor.committeememberNebel, Raymond L.en
dc.contributor.departmentAnimal and Poultry Sciencesen
dc.date.accessioned2014-03-14T20:40:36Zen
dc.date.adate2002-07-03en
dc.date.available2014-03-14T20:40:36Zen
dc.date.issued2002-06-07en
dc.date.rdate2003-07-03en
dc.date.sdate2002-06-27en
dc.description.abstractThe objective of this experiment was to examine the effects of varying the interval from follicular wave emergence to progestin removal on follicular dynamics and the synchrony of estrus. The experimental design was a 2x2x2 factorial with GnRH or estradiol-17 beta (E2) + progesterone (P4), controlled internal drug-releasing device (CIDR) treatment duration, and PG or saline treatment as main effects. Cycling, Angus cows (n=49), on d 6 to 8 of the estrous cycle, were randomly assigned to receive a CIDR treatment for 7 or 9 d. Approximately half of the cows from each CIDR group received either GnRH (100 mcg) or E2+P4 (1 mg E2 + 100 mg P4) at CIDR insertion. Cows in GnRH or E2+P4 groups were further divided into those that received PG (37.5 mg) or saline at CIDR insertion. All cows received PG (25 mg) 1 d prior to CIDR removal. The interval from follicular wave emergence to CIDR removal was longer for cows treated with GnRH (6.6 d) or a CIDR for 9 d (6.5 d) compared to those treated with E2+P4 (4.7 d) or a 7-d CIDR (4.8 d) (P < 0.05). Cows treated with PG or GnRH at CIDR insertion or a 9-d CIDR had a larger dominant follicle (DF) at CIDR removal than those treated with saline, E2+P4, or a 7-d CIDR. (P < 0.07). Altering the interval from wave emergence to progestin removal created differences in size of the DF at CIDR removal but did not affect the synchrony of estrus.en
dc.description.degreeMaster of Scienceen
dc.identifier.otheretd-06272002-113620en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-06272002-113620/en
dc.identifier.urihttp://hdl.handle.net/10919/33769en
dc.publisherVirginia Techen
dc.relation.haspartETD.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectGnRHen
dc.subjectestrus synchronizationen
dc.subjectestradiolen
dc.subjectfollicleen
dc.subjectprogestinen
dc.titleThe effects of varying the interval from follicular wave emergence to progestin withdrawal on follicular dynamics and the synchrony of estrus in beef cattleen
dc.typeThesisen
thesis.degree.disciplineAnimal and Poultry Sciencesen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
ETD.pdf
Size:
198.39 KB
Format:
Adobe Portable Document Format
Download

Collections

Masters Theses