Is progesterone the key regulatory factor behind ovulation rate in sheep?
Autor(a) principal: | |
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Data de Publicação: | 2017 |
Outros Autores: | , , , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1016/j.domaniend.2016.06.006 http://hdl.handle.net/11449/162288 |
Resumo: | Ovarian antral follicles in the ewe grow in an orderly succession, producing 3 to 4 waves per estrous cycle. In prolific sheep, some large antral follicles from the second-to-last wave of the estrous cycle are added to the ovulatory follicles emerging just before estrus to give a higher ovulation rate; it is feasible that regression of these follicles is prevented by an increase in serum concentrations of FSH or LH pulsatility at proestrus. Prolific sheep tend to have a shorter luteal phase than nonprolific ewes and there is a great deal of evidence that luteal progesterone (P-4), in addition to regulating LH release, may govern the secretion of FSH heralding the emergence of follicular waves. The specific purpose of this study was to determine whether or not extending the duration of the luteal phase in prolific sheep to that typically seen in nonprolific breeds would alter the follicle wave dynamics and ovulation rate. In 2 separate experiments, exogenous P-4 (7.5 mg per ewe intramuscularly) was administered on day 11 at PM and day 12 at AM (day 0 = first ovulation of the interovulatory interval studied) in moderately prolific Rideau Arcott x Polled Dorset ewes (experiment 1, n = 8) and highly prolific Olkuska ewes (experiment 2, n = 7; TRT), whereas the equinumerous groups of animals served as controls (CTR). Transrectal ovarian ultrasonography was performed daily, and jugular blood samples were drawn twice a day from day 9 until the next ovulation. Progesterone injections resulted in relatively uniform increments in serum P-4 levels, but the mean duration of the interovulatory interval did not differ (P > 0.05) between TRT and CTR groups of ewes in either experiment. The mean ovulation rate post-treatment was 1.6 +/- 0.2 vs 3.2 +/- 0.4 (experiment 1, P < 0.001) and 3.2 +/- 0.8 vs 4.0 +/- 1.0 (experiment 2, P > 0.05) in TRT vs CTR, respectively. The number and percentage of ovulating follicles from the penultimate wave of the interovulatory interval studied was 025 +/- 0.16 vs 1.75 +/- 0.45 (P < 0.01) and 25.0 +/- 16.4% vs 75.0 +/- 16.4% (P < 0.05) in experiment 1, and 0.50 +/- 0.30 vs 1.60 +/- 0.40 (P < 0.05) and 13.8 +/- 9.0% vs 53.4 +/- 16.7% (P < 0.05) in experiment 2, for TRT vs CTR, respectively. In summary, administration of P-4 at the end of diestrus decreased the incidence of ovulations from the penultimate wave of the estrous cycle in both the moderately and highly prolific strains of sheep, but it reduced the ovulation rate only in moderately prolific ewes. (C) 2016 Elsevier Inc. All rights reserved. |
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Is progesterone the key regulatory factor behind ovulation rate in sheep?SheepOvulation rateProgesteroneFSHUltrasonographyOvarian antral follicles in the ewe grow in an orderly succession, producing 3 to 4 waves per estrous cycle. In prolific sheep, some large antral follicles from the second-to-last wave of the estrous cycle are added to the ovulatory follicles emerging just before estrus to give a higher ovulation rate; it is feasible that regression of these follicles is prevented by an increase in serum concentrations of FSH or LH pulsatility at proestrus. Prolific sheep tend to have a shorter luteal phase than nonprolific ewes and there is a great deal of evidence that luteal progesterone (P-4), in addition to regulating LH release, may govern the secretion of FSH heralding the emergence of follicular waves. The specific purpose of this study was to determine whether or not extending the duration of the luteal phase in prolific sheep to that typically seen in nonprolific breeds would alter the follicle wave dynamics and ovulation rate. In 2 separate experiments, exogenous P-4 (7.5 mg per ewe intramuscularly) was administered on day 11 at PM and day 12 at AM (day 0 = first ovulation of the interovulatory interval studied) in moderately prolific Rideau Arcott x Polled Dorset ewes (experiment 1, n = 8) and highly prolific Olkuska ewes (experiment 2, n = 7; TRT), whereas the equinumerous groups of animals served as controls (CTR). Transrectal ovarian ultrasonography was performed daily, and jugular blood samples were drawn twice a day from day 9 until the next ovulation. Progesterone injections resulted in relatively uniform increments in serum P-4 levels, but the mean duration of the interovulatory interval did not differ (P > 0.05) between TRT and CTR groups of ewes in either experiment. The mean ovulation rate post-treatment was 1.6 +/- 0.2 vs 3.2 +/- 0.4 (experiment 1, P < 0.001) and 3.2 +/- 0.8 vs 4.0 +/- 1.0 (experiment 2, P > 0.05) in TRT vs CTR, respectively. The number and percentage of ovulating follicles from the penultimate wave of the interovulatory interval studied was 025 +/- 0.16 vs 1.75 +/- 0.45 (P < 0.01) and 25.0 +/- 16.4% vs 75.0 +/- 16.4% (P < 0.05) in experiment 1, and 0.50 +/- 0.30 vs 1.60 +/- 0.40 (P < 0.05) and 13.8 +/- 9.0% vs 53.4 +/- 16.7% (P < 0.05) in experiment 2, for TRT vs CTR, respectively. In summary, administration of P-4 at the end of diestrus decreased the incidence of ovulations from the penultimate wave of the estrous cycle in both the moderately and highly prolific strains of sheep, but it reduced the ovulation rate only in moderately prolific ewes. (C) 2016 Elsevier Inc. All rights reserved.Natural Sciences and Engineering Research Council of CanadaDepartment of Animal Biotechnology of the Agricultural University of Krakow, Cracow, PolandUniv Guelph, Dept Biomed Sci, Ontario Vet Coll, Guelph, ON, CanadaSao Paulo State Univ, Coll Agr & Vet Sci, Dept Preventat Vet Med & Anim Reprod, Jaboticabal, SP, BrazilAgr Univ Krakow, Dept Anim Biotechnol, Krakow, PolandAgr Univ Krakow, Dept Swine & Small Anim Breeding, Krakow, PolandUniv Missouri, Anim Sci Res Ctr, Columbia, MO USASao Paulo State Univ, Coll Agr & Vet Sci, Dept Preventat Vet Med & Anim Reprod, Jaboticabal, SP, BrazilElsevier B.V.Univ GuelphUniversidade Estadual Paulista (Unesp)Agr Univ KrakowUniv MissouriBartlewski, P. M.Sohal, J.Paravinja, V.Baby, T.Oliveira, M. E. F. [UNESP]Murawski, M.Schwarz, T.Zieba, D. A.Keisler, D. H.2018-11-26T17:15:29Z2018-11-26T17:15:29Z2017-01-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article30-38application/pdfhttp://dx.doi.org/10.1016/j.domaniend.2016.06.006Domestic Animal Endocrinology. New York: Elsevier Science Inc, v. 58, p. 30-38, 2017.0739-7240http://hdl.handle.net/11449/16228810.1016/j.domaniend.2016.06.006WOS:000390729200004WOS000390729200004.pdfWeb of Sciencereponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengDomestic Animal Endocrinology0,887info:eu-repo/semantics/openAccess2023-10-05T06:05:13Zoai:repositorio.unesp.br:11449/162288Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462023-10-05T06:05:13Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Is progesterone the key regulatory factor behind ovulation rate in sheep? |
title |
Is progesterone the key regulatory factor behind ovulation rate in sheep? |
spellingShingle |
Is progesterone the key regulatory factor behind ovulation rate in sheep? Bartlewski, P. M. Sheep Ovulation rate Progesterone FSH Ultrasonography |
title_short |
Is progesterone the key regulatory factor behind ovulation rate in sheep? |
title_full |
Is progesterone the key regulatory factor behind ovulation rate in sheep? |
title_fullStr |
Is progesterone the key regulatory factor behind ovulation rate in sheep? |
title_full_unstemmed |
Is progesterone the key regulatory factor behind ovulation rate in sheep? |
title_sort |
Is progesterone the key regulatory factor behind ovulation rate in sheep? |
author |
Bartlewski, P. M. |
author_facet |
Bartlewski, P. M. Sohal, J. Paravinja, V. Baby, T. Oliveira, M. E. F. [UNESP] Murawski, M. Schwarz, T. Zieba, D. A. Keisler, D. H. |
author_role |
author |
author2 |
Sohal, J. Paravinja, V. Baby, T. Oliveira, M. E. F. [UNESP] Murawski, M. Schwarz, T. Zieba, D. A. Keisler, D. H. |
author2_role |
author author author author author author author author |
dc.contributor.none.fl_str_mv |
Univ Guelph Universidade Estadual Paulista (Unesp) Agr Univ Krakow Univ Missouri |
dc.contributor.author.fl_str_mv |
Bartlewski, P. M. Sohal, J. Paravinja, V. Baby, T. Oliveira, M. E. F. [UNESP] Murawski, M. Schwarz, T. Zieba, D. A. Keisler, D. H. |
dc.subject.por.fl_str_mv |
Sheep Ovulation rate Progesterone FSH Ultrasonography |
topic |
Sheep Ovulation rate Progesterone FSH Ultrasonography |
description |
Ovarian antral follicles in the ewe grow in an orderly succession, producing 3 to 4 waves per estrous cycle. In prolific sheep, some large antral follicles from the second-to-last wave of the estrous cycle are added to the ovulatory follicles emerging just before estrus to give a higher ovulation rate; it is feasible that regression of these follicles is prevented by an increase in serum concentrations of FSH or LH pulsatility at proestrus. Prolific sheep tend to have a shorter luteal phase than nonprolific ewes and there is a great deal of evidence that luteal progesterone (P-4), in addition to regulating LH release, may govern the secretion of FSH heralding the emergence of follicular waves. The specific purpose of this study was to determine whether or not extending the duration of the luteal phase in prolific sheep to that typically seen in nonprolific breeds would alter the follicle wave dynamics and ovulation rate. In 2 separate experiments, exogenous P-4 (7.5 mg per ewe intramuscularly) was administered on day 11 at PM and day 12 at AM (day 0 = first ovulation of the interovulatory interval studied) in moderately prolific Rideau Arcott x Polled Dorset ewes (experiment 1, n = 8) and highly prolific Olkuska ewes (experiment 2, n = 7; TRT), whereas the equinumerous groups of animals served as controls (CTR). Transrectal ovarian ultrasonography was performed daily, and jugular blood samples were drawn twice a day from day 9 until the next ovulation. Progesterone injections resulted in relatively uniform increments in serum P-4 levels, but the mean duration of the interovulatory interval did not differ (P > 0.05) between TRT and CTR groups of ewes in either experiment. The mean ovulation rate post-treatment was 1.6 +/- 0.2 vs 3.2 +/- 0.4 (experiment 1, P < 0.001) and 3.2 +/- 0.8 vs 4.0 +/- 1.0 (experiment 2, P > 0.05) in TRT vs CTR, respectively. The number and percentage of ovulating follicles from the penultimate wave of the interovulatory interval studied was 025 +/- 0.16 vs 1.75 +/- 0.45 (P < 0.01) and 25.0 +/- 16.4% vs 75.0 +/- 16.4% (P < 0.05) in experiment 1, and 0.50 +/- 0.30 vs 1.60 +/- 0.40 (P < 0.05) and 13.8 +/- 9.0% vs 53.4 +/- 16.7% (P < 0.05) in experiment 2, for TRT vs CTR, respectively. In summary, administration of P-4 at the end of diestrus decreased the incidence of ovulations from the penultimate wave of the estrous cycle in both the moderately and highly prolific strains of sheep, but it reduced the ovulation rate only in moderately prolific ewes. (C) 2016 Elsevier Inc. All rights reserved. |
publishDate |
2017 |
dc.date.none.fl_str_mv |
2017-01-01 2018-11-26T17:15:29Z 2018-11-26T17:15:29Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.1016/j.domaniend.2016.06.006 Domestic Animal Endocrinology. New York: Elsevier Science Inc, v. 58, p. 30-38, 2017. 0739-7240 http://hdl.handle.net/11449/162288 10.1016/j.domaniend.2016.06.006 WOS:000390729200004 WOS000390729200004.pdf |
url |
http://dx.doi.org/10.1016/j.domaniend.2016.06.006 http://hdl.handle.net/11449/162288 |
identifier_str_mv |
Domestic Animal Endocrinology. New York: Elsevier Science Inc, v. 58, p. 30-38, 2017. 0739-7240 10.1016/j.domaniend.2016.06.006 WOS:000390729200004 WOS000390729200004.pdf |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Domestic Animal Endocrinology 0,887 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
30-38 application/pdf |
dc.publisher.none.fl_str_mv |
Elsevier B.V. |
publisher.none.fl_str_mv |
Elsevier B.V. |
dc.source.none.fl_str_mv |
Web of Science reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
|
_version_ |
1792961467792752640 |