Follicular wave dynamics after estradiol-17β treatment of heifers with or without a progestogen implant

dc.creatorBo, G.A.
dc.creatorAdams, G.P.
dc.creatorPierson, R.A.
dc.creatorTribulo, Humberto Elías
dc.creatorCaccia, M.
dc.creatorMapletoft, R.J.
dc.date1994-12-31
dc.date.accessioned2023-08-30T17:08:34Z
dc.date.available2023-08-30T17:08:34Z
dc.identifierhttp://pa.bibdigital.ucc.edu.ar/3713/1/A_Bo_Adams_Pierson_Tribulo_Caccia_Mapletoft.pdf
dc.identifier.urihttps://repositorioslatinoamericanos.uchile.cl/handle/2250/8539442
dc.descriptionTwo experiments were designed to evaluate the effects of estradiol-17β (E-17β) on follicular wave dynamics and gonadotropin in cattle. The first experiment was designed to evaluate the effect of 5 mg E-17β administered on Day 1 (ovulation=Day 0) in heifers with or without a progestogen (SMB) ear implant. The dominant follicle in heifers treated with E-17β+SMB ceased to grow 1 d after E-17β treatment and subsequently regressed resulting in early emergence of the next follicular wave. Conversely, E-17β treatment of non-implanted heifers resulted in transient or incomplete suppression of the dominant follicle, and delayed emergence of the next follicular wave (P<0.05). A post-treatment surge in plasma LH concentration was detected in 5 of 6 heifers treated with E-17β alone versus 1 of 6 treated with E-17β+SMB (P<0.05). In all but 1 heifer, the LH surge was accompanied by a concurrent FSH surge (18 to 36 h after E-17β). The second experiment was designed to determine an effective dosage regimen of E-17β for suppression of follicular growth in SMB-implanted heifers and to test the hypothesis that estradiol-induced follicle suppression will result in a synchronous emergence of the subsequent follicular wave. On Day 0,48 heifers were implanted with SMB and allocated to 1 of 7 treatment groups: control heifers, and those that received 10 mg or 5 mg E-17β i.m. on Day 1 or Day 3; or 2.5 mg E-17β b.i.d. on Days 1 to 3 or Days 3 to 5. The growth of the dominant follicle of the first follicular wave was suppressed in all the E-17β treated groups. Emergence of the second follicular wave was later (P<0.05) in control heifers than heifers treated with a single injection of E-17β on Day 1, but was not different from heifers treated on Day 3. Furthermore, the day of wave emergence was less variable (P<0.05) in heifers treated with 5 mg of E-17β than in control heifers. It was concluded that E-17β and progestogen treatment may be used to suppress follicular growth and cause the synchronous emergence of a new follicular wave in cattle.
dc.descriptionFil: Bo, G.A. University of Saskatchewan; Canadá
dc.descriptionFil: Adams, G.P. University of Saskatchewan; Canadá
dc.descriptionFil: Pierson, R.A. University of Saskatchewan; Canadá
dc.descriptionFil: Tribulo, Humberto Elías. Universidad Católica de Córdoba. Facultad de Ciencias Agropecuarias; Argentina
dc.descriptionFil: Caccia, M. Universidad Católica de Córdoba. Facultad de Ciencias Agropecuarias; Argentina
dc.descriptionFil: Mapletoft, R.J. University of Saskatchewan; Canadá
dc.formatapplication/pdf
dc.languagespa
dc.relationhttp://pa.bibdigital.ucc.edu.ar/3713/
dc.relationinfo:eu-repo/semantics/altIdentifier/doi/10.1016/0093-691X(94)90821-Y
dc.rightsinfo:eu-repo/semantics/openAccess
dc.rightshttps://creativecommons.org/licenses/by-nc-nd/4.0/deed.es
dc.sourceBo, G.A., Adams, G.P., Pierson, R.A., Tribulo, Humberto Elías ORCID: https://orcid.org/0000-0002-3192-1959 <https://orcid.org/0000-0002-3192-1959>, Caccia, M. and Mapletoft, R.J. (1994) Follicular wave dynamics after estradiol-17β treatment of heifers with or without a progestogen implant. Theriogenology, 41 (8). pp. 1555-1569. ISSN 0093-691X
dc.subjectSB Cultura de la planta
dc.titleFollicular wave dynamics after estradiol-17β treatment of heifers with or without a progestogen implant
dc.typeinfo:eu-repo/semantics/article
dc.typeinfo:ar-repo/semantics/artículo
dc.typeinfo:eu-repo/semantics/acceptedVersion


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