Luteotropic effects of human chorionic gonadotropin administered 7.5 days after synchronous estrous induction in Morada Nova ewes.

Autor: Vergani GB; Department of Pathobiology and Veterinary Theriogenology, School of Agricultural and Veterinarian Sciences, São Paulo State University, Jaboticabal, SP, Brazil., Fonseca JFD; Embrapa Caprinos e Ovinos, Rodovia MG 133, Km 42, Cep 36.155-000, Coronel Pacheco, MG, Brazil; Departamento de Veterinária, Universidade Federal de Viçosa, Av. Peter Henry Rolfs, s/n, CEP 36570-000, Viçosa, MG, Brazil. Electronic address: jeferson.fonseca@embrapa.br., Trevizan JT; Department of Pathobiology and Veterinary Theriogenology, School of Agricultural and Veterinarian Sciences, São Paulo State University, Jaboticabal, SP, Brazil., Pereira VSDA; Embrapa Pecuária Sudeste, Rodovia Washington Luiz, Km 234 s/nº, Fazenda Canchim, Caixa Postal: 339, CEP: 13560-970, São Carlos, SP, Brazil., Garcia AR; Embrapa Pecuária Sudeste, Rodovia Washington Luiz, Km 234 s/nº, Fazenda Canchim, Caixa Postal: 339, CEP: 13560-970, São Carlos, SP, Brazil., Esteves SN; Embrapa Pecuária Sudeste, Rodovia Washington Luiz, Km 234 s/nº, Fazenda Canchim, Caixa Postal: 339, CEP: 13560-970, São Carlos, SP, Brazil., Brandão FZ; Faculdade de Veterinária, Universidade Federal Fluminense, Rua Vital Brasil Filho, 64, CEP 24230-340, Niterói, RJ, Brazil., Souza-Fabjan JMG; Faculdade de Veterinária, Universidade Federal Fluminense, Rua Vital Brasil Filho, 64, CEP 24230-340, Niterói, RJ, Brazil., Oliveira MEF; Department of Pathobiology and Veterinary Theriogenology, School of Agricultural and Veterinarian Sciences, São Paulo State University, Jaboticabal, SP, Brazil; Embrapa Caprinos e Ovinos, Rodovia MG 133, Km 42, Cep 36.155-000, Coronel Pacheco, MG, Brazil. Electronic address: m_emiliafraoli@yahoo.com.br.
Jazyk: angličtina
Zdroj: Animal reproduction science [Anim Reprod Sci] 2020 Dec; Vol. 223, pp. 106644. Date of Electronic Publication: 2020 Nov 02.
DOI: 10.1016/j.anireprosci.2020.106644
Abstrakt: This study was conducted in ewes to assess effects of human chorionic gonadotropin (hCG) administration after imposing an estrous induction treatment regimen. Ewes (n = 115) were treated with a 60 mg medroxyprogesterone-intravaginal-sponge for 6 d plus 200 IU of equine chorionic gonadotropin (eCG) im and 37.5 μg d-cloprostenol im 36 h before sponge removal (Day 0). After natural mating, ewes having at least one corpus luteum (CL; n = 108) were administered either 1 mL of saline (G-Control; n = 53) or 300 IU of hCG (G-hCG; n = 55) on Day 7.5 after sponge removal (Day 0). Ovarian ultrasonography and blood collection were performed on Days 7.5, 13.5, 17.5, 21.5, and 30.5. Accessory CL (aCL) were observed in 81.5 % (G-hCG) and 0.0 % (G-Control) of ewes (P = 0.0001). Diameter, area, and volume of luteal tissue were greater (P < 0.05) in G-hCG from Day 13.5 to 30.5. Progesterone (P 4 ) concentrations were greater (P < 0.05) on Days 13.5, 17.5, 21.5 and 30.5 for ewes of the G-hCG group. Pregnancy percentage was similar (P = 0.25) between groups [47.1 % (G-control) compared with 60.0 % (G-hCG)], although total number of lambs produced by estrous synchronized ewes was greater (P = 0.005) in ewes of the G-hCG group (90.9 % compared with 66.0 %). In conclusion, hCG administration 7.5 days after sponge removal from Morada Nova ewes during the non-breeding season is an effective treatment to induce aCL formation, improve luteal tissue biometry and P4 concentrations, and to enhance the total number of lambs born.
(Copyright © 2020 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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