Effect of timing of estradiol benzoate administration upon synchronization of ovulation in suckling Nelore cows (Bos indicus) treated with a progesterone-releasing intravaginal device

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MetadadosDescriçãoIdioma
Autor(es): dc.contributorUniversidade Estadual Paulista (UNESP)-
Autor(es): dc.creatorAyres, H.-
Autor(es): dc.creatorMartins, C. M.-
Autor(es): dc.creatorFerreira, R. M.-
Autor(es): dc.creatorMello, J. E.-
Autor(es): dc.creatorDominguez, J. H.-
Autor(es): dc.creatorSouza, A. H.-
Autor(es): dc.creatorValentin, R.-
Autor(es): dc.creatorSantos, I. C. C.-
Autor(es): dc.creatorBaruselli, P. S.-
Data de aceite: dc.date.accessioned2021-03-10T16:35:48Z-
Data de disponibilização: dc.date.available2021-03-10T16:35:48Z-
Data de envio: dc.date.issued2014-05-20-
Data de envio: dc.date.issued2014-05-20-
Data de envio: dc.date.issued2008-12-01-
Fonte completa do material: dc.identifierhttp://dx.doi.org/10.1016/j.anireprosci.2007.12.001-
Fonte completa do material: dc.identifierhttp://hdl.handle.net/11449/2536-
Fonte: dc.identifier.urihttp://educapes.capes.gov.br/handle/11449/2536-
Descrição: dc.descriptionFazenda Santa Barbara-
Descrição: dc.descriptionPocos de Caldas/MG-
Descrição: dc.descriptionFazenda Santa Eliza-
Descrição: dc.descriptionCampo Grande-
Descrição: dc.descriptionTecnopec Cons C. R. Ltda-
Descrição: dc.descriptionThe present study investigated how the timing of the administration of estradiol benzoate (EB) impacted the synchronization of ovulation in fixed-time artificial insemination protocols of cattle. To accomplish this, two experiments were conducted, with EB injection occurring at different times: at withdrawal of the progesterone-releasing (N) intravaginal device or 24 h later. The effectiveness of these times was compared by examining ovarian follicular dynamics (Experiment 1, n = 30) and conception rates (Experiment 2, n = 504). In Experiment 1, follicular dynamics was performed in 30 Nelore cows (Bos indicus) allocated into two groups. on a random day of the estrous cycle (Day 0), both groups received 2 mg of EB i.m. and a P4-releasing intravaginal device, which was removed on Day 8, when 400 IU of eCG and 150 mu g of PGF were administered. The control group (G-EB9; n = 15) received 1 mg of EB on Day 9, while Group EB8 (G-EB8; n = 15) received the same dose a day earlier. Ovarian ultrasonographic evaluations were performed every 8 h after device removal until ovulation. The timing of EB administration (Day 8 compared with Day 9) did affect the interval between P4 device removal to ovulation (59.4 +/- 2.0 h compared with 69.3 +/- 1.7 h) and maximum diameter of dominant (1.54 +/- 0.06 a cm compared with 1.71 +/- 0.05 b cm, P = 0.03) and ovulatory (1.46 +/- 0.05 a cm compared with 1.58 +/- 0.04 b cm, P < 0.01) follicles. In Experiment 2,504 suckling cows received the same treatment described in Experiment 1, but insemination was performed as follows: Group EB8-AI48h (G-EB8-AI48h; n = 119) and Group EB8-AI54h (G-EB8-AI54h; n = 134) received 1 mg of EB on Day 8 and FrAI was performed, respectively, 48 or 54 h after P4 device removal. Group EB9-AI48h (G-EB9-AI48h; n = 126) and Group EB9-AI54h (G-EB9-AI54h n = 125) received the same treatments and underwent the same FTAI protocols as G-EB8-AI48h and G-EB8-AI54h, respectively; however, EB was administered on Day 9. Conception rates were greater (P < 0.05) in G-EB9-AI54h 163.2% (79/125) a], G-EB9-AI48h [58.7% (74/126) a] and G-EB8-AI48h [58.8% (70/119) a] than in G-EB8-AI54h [34.3% (46/134) b]. We concluded that when EB administration occurred at device withdrawal (D8), the interval to ovulation shortened and dominant and ovulatory follicle diameters decreased. Furthermore, when EB treatment was performed 24 h after device removal, FTAI conducted at either 48 or 54 h resulted in similar conception rates. However, EB treatment on the same day as device withdrawal resulted in a lesser conception rate when FTAI was conducted 54 h after device removal. (C) 2007 Elsevier B.V. All rights reserved.-
Formato: dc.format77-87-
Idioma: dc.languageen-
Publicador: dc.publisherElsevier B.V.-
Relação: dc.relationAnimal Reproduction Science-
Relação: dc.relation1.647-
Relação: dc.relation0,704-
Direitos: dc.rightsclosedAccess-
Palavras-chave: dc.subjectCattle-fixed-time artificial insemination-
Palavras-chave: dc.subjectFollicular dynamics-
Palavras-chave: dc.subjectovulation-
Palavras-chave: dc.subjectPregnancy-
Palavras-chave: dc.subjectEstradiol benzoate-
Título: dc.titleEffect of timing of estradiol benzoate administration upon synchronization of ovulation in suckling Nelore cows (Bos indicus) treated with a progesterone-releasing intravaginal device-
Tipo de arquivo: dc.typelivro digital-
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