Effects of additional gonadotropin-releasing hormone and prostaglandin F2α treatment to an estradiol/progesterone-based embryo transfer protocol for recipient lactating dairy cows

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MetadadosDescriçãoIdioma
Autor(es): dc.contributorUniversidade Estadual Paulista (UNESP)-
Autor(es): dc.contributorChr. Hansen Animal Health & Nutrition-
Autor(es): dc.contributorUniversity of British Columbia-
Autor(es): dc.contributorUniversity of Florida-
Autor(es): dc.creatorPereira, M. H.C.-
Autor(es): dc.creatorCappellozza, B. I.-
Autor(es): dc.creatorCerri, R. L.A.-
Autor(es): dc.creatorSanches, C. P.-
Autor(es): dc.creatorGuida, T. G.-
Autor(es): dc.creatorBarbosa, L. F.S.P.-
Autor(es): dc.creatorSantos, J. E.P.-
Autor(es): dc.creatorVasconcelos, J. L.M.-
Data de aceite: dc.date.accessioned2025-08-21T22:51:36Z-
Data de disponibilização: dc.date.available2025-08-21T22:51:36Z-
Data de envio: dc.date.issued2023-07-29-
Data de envio: dc.date.issued2023-07-29-
Data de envio: dc.date.issued2023-01-31-
Fonte completa do material: dc.identifierhttp://dx.doi.org/10.3168/jds.2022-22134-
Fonte completa do material: dc.identifierhttp://hdl.handle.net/11449/246702-
Fonte: dc.identifier.urihttp://educapes.capes.gov.br/handle/11449/246702-
Descrição: dc.descriptionThis study was designed to evaluate whether the utilization of a second PGF2α treatment at the end of an estradiol/progesterone (E2/P4)-based protocol with or without GnRH at the beginning of the protocol would improve pregnancy rates of lactating Holstein cows assigned to timed embryo transfer. A total of 501 lactating Holstein cows in 5 farms were enrolled in the experiment. Within farm, cows were blocked by parity and, within block, were assigned randomly to (1) insertion of an intravaginal P4 device (controlled internal drug-releasing device; CIDR) and estradiol benzoate on d −11, PGF2α on d −4, CIDR withdrawal and an injection of estradiol cypionate on d −2, and timed embryo transfer on d 7 (1-PGF; n = 164); (2) the same treatments as 1-PGF, but with PGF2α administered on d −4 and −2 (2-PGF; n = 171); and (3) 2-PGF with the addition of a GnRH treatment on d −11 (GnRH+2-PGF; n = 166). Ovaries were scanned by transrectal ultrasonography on d −11, −4, and 7, and blood samples were collected on d −11, −4, 0, and 7 for P4 determination. Treatment comparisons were performed using contrasts. The proportion of cows with a new corpus luteum on d −4 was greater in GnRH+2-PGF cows. Cows in 1-PGF had a greater P4 concentration on d 0 but lesser P4 on d 7 compared with cows in the other groups. Cows assigned to receive 2-PGF (2-PGF and GnRH+2-PGF) had greater estrus expression, and a greater proportion of cows ovulated to estradiol cypionate. No further contrast effects were observed for follicle diameter, double ovulation rate, pregnancy per embryo transfer (P/ET) on d 32 and 60, or pregnancy loss. As P4 concentration on d −4 increased, P/ET on d 60 tended to increase. Cows with P4 ≥3.66 ng/mL on d −4 had greater P/ET on d 32 and 60 than those with P4 below that threshold. Regardless of treatment, cows with P4 concentration ≥3.66 ng/mL also had a greater pregnancy per synchronized protocol (P/SP) on d 60. Also, a P4 concentration on d −4 (low or high) × follicle diameter (continuous) interaction tendency was observed when evaluating P/ET. Although P/ET did not differ among cows with different follicles sizes with reduced P4 concentration on d −4 (<3.66 ng/mL), it increased in cows with larger follicles exposed to increased P4 concentration (≥3.66 ng/mL). When P4 on d 0 was evaluated, P/ET on d 32 and 60 was greater for cows with low (≤0.09 ng/mL) versus high (>0.21 ng/mL) P4; as P4 concentration on d 0 increased, P/ET linearly decreased. In summary, cows with increased P4 concentrations during growth of the ovulatory follicular wave had improved P/ET. Administering a second PGF2α dose reduced P4 concentration on d 0 and increased ovulatory response to the protocol, but no benefits were observed on P/ET or P/SP.-
Descrição: dc.descriptionFaculdade de Medicina Veterinária e Zootecnia Universidade Estadual Paulista (UNESP), SP-
Descrição: dc.descriptionChr. Hansen Animal Health & Nutrition-
Descrição: dc.descriptionFaculty of Land and Food Systems University of British Columbia-
Descrição: dc.descriptionDepartment of Animal Sciences D.H. Barron Reproductive and Perinatal Biology Research Program University of Florida-
Descrição: dc.descriptionDepartment of Animal Production São Paulo State University-
Descrição: dc.descriptionFaculdade de Medicina Veterinária e Zootecnia Universidade Estadual Paulista (UNESP), SP-
Descrição: dc.descriptionDepartment of Animal Production São Paulo State University-
Formato: dc.format1414-1428-
Idioma: dc.languageen-
Relação: dc.relationJournal of Dairy Science-
???dc.source???: dc.sourceScopus-
Palavras-chave: dc.subjectembryo transfer-
Palavras-chave: dc.subjectgonadotropin-releasing hormone-
Palavras-chave: dc.subjectprogesterone-
Palavras-chave: dc.subjectprostaglandin-
Título: dc.titleEffects of additional gonadotropin-releasing hormone and prostaglandin F2α treatment to an estradiol/progesterone-based embryo transfer protocol for recipient lactating dairy cows-
Tipo de arquivo: dc.typelivro digital-
Aparece nas coleções:Repositório Institucional - Unesp

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