Does GnRH treatment at TAI regardless of estrus occurrence increase pregnancy rate in crossbred Bos taurus suckled cows?
Autor(a) principal: | |
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Data de Publicação: | 2024 |
Outros Autores: | , , , , , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UFRGS |
Texto Completo: | http://hdl.handle.net/10183/274721 |
Resumo: | The impact of GnRH treatment on the day of TAI in beef cows has received limited investigation, especially concerning its association with estrus expression. Consequently, two experiments were conducted to assess the potential of GnRH treatment on the day of TAI to enhance fertility according to the expression or not of estrus in beef cows. Experiment 1 aimed to determine ovulation rate and luteal function, while Experiment 2 aimed to determine the effect of the two GnRH treatment approaches on pregnancy rate. In Experiment 1, multiparous Brangus suckling cows (n = 17) were submitted to an 8-day TAI protocol. Estrus occurrence was evaluated based on chalk removal on D10 (TAI) and cows were assigned to receive GnRH (25μg lecirelin; im) according to the group: GnRH (n = 7), regardless of estrus expression; or selectGnRH (n = 10), only cows not detected in estrus. Ovulation rate occurring until 77h after IVD removal did not differ (p = 0.17) between GnRH (85.7%; 6/7) and selectGnRH (100%; 10/10). Also, corpus luteum size and serum progesterone concentration were not affected (p>0.05) by treatments. In Experiment 2, crossbred taurine suckled cows (n = 384) were submitted to the same protocol as described in Experiment 1 and were randomly allocated to GnRH or selectGnRH groups. There was no difference in P/AI between groups (selectGnRH = 55.6%; GnRH = 54.3%; p = 0.7) 30 days after TAI. As expected, there was a pronounced effect (p<0.0001) of estrus expression on P/AI (Estrus = 61.5%; No estrus = 33.0%), regardless of group. In summary, ovulation timing and rate and luteal function did not differ between groups. Also, GnRH administration only in cows that do not show estrus is recommended, considering hormone savings and similar conception rate. |
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Fernandes, Vanessa SilvaVelho, Gabriella dos SantosSantos, Mateus Felipe Osório dosEvangelista, Kelly AlvesGasperin, Bernardo GarzieraPfeifer, Luiz Francisco MachadoFerreira, RogérioGoncalves, Paulo Bayard DiasGastal, Gustavo Desire AntunesDalto, André Gustavo CabreraRovani, Monique Tomazele2024-04-12T06:21:13Z20241806-9614http://hdl.handle.net/10183/274721001200461The impact of GnRH treatment on the day of TAI in beef cows has received limited investigation, especially concerning its association with estrus expression. Consequently, two experiments were conducted to assess the potential of GnRH treatment on the day of TAI to enhance fertility according to the expression or not of estrus in beef cows. Experiment 1 aimed to determine ovulation rate and luteal function, while Experiment 2 aimed to determine the effect of the two GnRH treatment approaches on pregnancy rate. In Experiment 1, multiparous Brangus suckling cows (n = 17) were submitted to an 8-day TAI protocol. Estrus occurrence was evaluated based on chalk removal on D10 (TAI) and cows were assigned to receive GnRH (25μg lecirelin; im) according to the group: GnRH (n = 7), regardless of estrus expression; or selectGnRH (n = 10), only cows not detected in estrus. Ovulation rate occurring until 77h after IVD removal did not differ (p = 0.17) between GnRH (85.7%; 6/7) and selectGnRH (100%; 10/10). Also, corpus luteum size and serum progesterone concentration were not affected (p>0.05) by treatments. In Experiment 2, crossbred taurine suckled cows (n = 384) were submitted to the same protocol as described in Experiment 1 and were randomly allocated to GnRH or selectGnRH groups. There was no difference in P/AI between groups (selectGnRH = 55.6%; GnRH = 54.3%; p = 0.7) 30 days after TAI. As expected, there was a pronounced effect (p<0.0001) of estrus expression on P/AI (Estrus = 61.5%; No estrus = 33.0%), regardless of group. In summary, ovulation timing and rate and luteal function did not differ between groups. Also, GnRH administration only in cows that do not show estrus is recommended, considering hormone savings and similar conception rate.application/pdfengAnimal reproduction. Belo Horizonte. Vol. 21, no. 1 (2024), e20230123, 7 p.Hormônio liberador de gonadotropinaInseminação artificial em tempo fixo (IATF)EstroOvulaçãoCorpo lúteoPrenhezBovinosGnRHTimed artificial inseminationEstrusOvulationConception rateDoes GnRH treatment at TAI regardless of estrus occurrence increase pregnancy rate in crossbred Bos taurus suckled cows?info:eu-repo/semantics/articleinfo:eu-repo/semantics/otherinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRGSinstname:Universidade Federal do Rio Grande do Sul (UFRGS)instacron:UFRGSTEXT001200461.pdf.txt001200461.pdf.txtExtracted Texttext/plain24451http://www.lume.ufrgs.br/bitstream/10183/274721/2/001200461.pdf.txt0ff1b43d64224ab30c71bb50c0bbe7f5MD52ORIGINAL001200461.pdfTexto completo (inglês)application/pdf657917http://www.lume.ufrgs.br/bitstream/10183/274721/1/001200461.pdffc748df7b833c9abcfd6387cb91461ffMD5110183/2747212024-04-13 06:46:12.170311oai:www.lume.ufrgs.br:10183/274721Repositório de PublicaçõesPUBhttps://lume.ufrgs.br/oai/requestopendoar:2024-04-13T09:46:12Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS)false |
dc.title.pt_BR.fl_str_mv |
Does GnRH treatment at TAI regardless of estrus occurrence increase pregnancy rate in crossbred Bos taurus suckled cows? |
title |
Does GnRH treatment at TAI regardless of estrus occurrence increase pregnancy rate in crossbred Bos taurus suckled cows? |
spellingShingle |
Does GnRH treatment at TAI regardless of estrus occurrence increase pregnancy rate in crossbred Bos taurus suckled cows? Fernandes, Vanessa Silva Hormônio liberador de gonadotropina Inseminação artificial em tempo fixo (IATF) Estro Ovulação Corpo lúteo Prenhez Bovinos GnRH Timed artificial insemination Estrus Ovulation Conception rate |
title_short |
Does GnRH treatment at TAI regardless of estrus occurrence increase pregnancy rate in crossbred Bos taurus suckled cows? |
title_full |
Does GnRH treatment at TAI regardless of estrus occurrence increase pregnancy rate in crossbred Bos taurus suckled cows? |
title_fullStr |
Does GnRH treatment at TAI regardless of estrus occurrence increase pregnancy rate in crossbred Bos taurus suckled cows? |
title_full_unstemmed |
Does GnRH treatment at TAI regardless of estrus occurrence increase pregnancy rate in crossbred Bos taurus suckled cows? |
title_sort |
Does GnRH treatment at TAI regardless of estrus occurrence increase pregnancy rate in crossbred Bos taurus suckled cows? |
author |
Fernandes, Vanessa Silva |
author_facet |
Fernandes, Vanessa Silva Velho, Gabriella dos Santos Santos, Mateus Felipe Osório dos Evangelista, Kelly Alves Gasperin, Bernardo Garziera Pfeifer, Luiz Francisco Machado Ferreira, Rogério Goncalves, Paulo Bayard Dias Gastal, Gustavo Desire Antunes Dalto, André Gustavo Cabrera Rovani, Monique Tomazele |
author_role |
author |
author2 |
Velho, Gabriella dos Santos Santos, Mateus Felipe Osório dos Evangelista, Kelly Alves Gasperin, Bernardo Garziera Pfeifer, Luiz Francisco Machado Ferreira, Rogério Goncalves, Paulo Bayard Dias Gastal, Gustavo Desire Antunes Dalto, André Gustavo Cabrera Rovani, Monique Tomazele |
author2_role |
author author author author author author author author author author |
dc.contributor.author.fl_str_mv |
Fernandes, Vanessa Silva Velho, Gabriella dos Santos Santos, Mateus Felipe Osório dos Evangelista, Kelly Alves Gasperin, Bernardo Garziera Pfeifer, Luiz Francisco Machado Ferreira, Rogério Goncalves, Paulo Bayard Dias Gastal, Gustavo Desire Antunes Dalto, André Gustavo Cabrera Rovani, Monique Tomazele |
dc.subject.por.fl_str_mv |
Hormônio liberador de gonadotropina Inseminação artificial em tempo fixo (IATF) Estro Ovulação Corpo lúteo Prenhez Bovinos |
topic |
Hormônio liberador de gonadotropina Inseminação artificial em tempo fixo (IATF) Estro Ovulação Corpo lúteo Prenhez Bovinos GnRH Timed artificial insemination Estrus Ovulation Conception rate |
dc.subject.eng.fl_str_mv |
GnRH Timed artificial insemination Estrus Ovulation Conception rate |
description |
The impact of GnRH treatment on the day of TAI in beef cows has received limited investigation, especially concerning its association with estrus expression. Consequently, two experiments were conducted to assess the potential of GnRH treatment on the day of TAI to enhance fertility according to the expression or not of estrus in beef cows. Experiment 1 aimed to determine ovulation rate and luteal function, while Experiment 2 aimed to determine the effect of the two GnRH treatment approaches on pregnancy rate. In Experiment 1, multiparous Brangus suckling cows (n = 17) were submitted to an 8-day TAI protocol. Estrus occurrence was evaluated based on chalk removal on D10 (TAI) and cows were assigned to receive GnRH (25μg lecirelin; im) according to the group: GnRH (n = 7), regardless of estrus expression; or selectGnRH (n = 10), only cows not detected in estrus. Ovulation rate occurring until 77h after IVD removal did not differ (p = 0.17) between GnRH (85.7%; 6/7) and selectGnRH (100%; 10/10). Also, corpus luteum size and serum progesterone concentration were not affected (p>0.05) by treatments. In Experiment 2, crossbred taurine suckled cows (n = 384) were submitted to the same protocol as described in Experiment 1 and were randomly allocated to GnRH or selectGnRH groups. There was no difference in P/AI between groups (selectGnRH = 55.6%; GnRH = 54.3%; p = 0.7) 30 days after TAI. As expected, there was a pronounced effect (p<0.0001) of estrus expression on P/AI (Estrus = 61.5%; No estrus = 33.0%), regardless of group. In summary, ovulation timing and rate and luteal function did not differ between groups. Also, GnRH administration only in cows that do not show estrus is recommended, considering hormone savings and similar conception rate. |
publishDate |
2024 |
dc.date.accessioned.fl_str_mv |
2024-04-12T06:21:13Z |
dc.date.issued.fl_str_mv |
2024 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/other |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10183/274721 |
dc.identifier.issn.pt_BR.fl_str_mv |
1806-9614 |
dc.identifier.nrb.pt_BR.fl_str_mv |
001200461 |
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1806-9614 001200461 |
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http://hdl.handle.net/10183/274721 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.ispartof.pt_BR.fl_str_mv |
Animal reproduction. Belo Horizonte. Vol. 21, no. 1 (2024), e20230123, 7 p. |
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info:eu-repo/semantics/openAccess |
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