Influence of the dominant follicle on the ovarian follicular dynamics in Nelore cows treated with FSH
The objectives of this study were: (1) to determine the maximum diameter and the growth rate of the dominant follicle (DF) in Nelore cows; (2) to determine the interval between PGF2;µ; administration and the manifestation of estrus; (3) to investigate the influence of the DF removal on the number of...
| Autores: | , , , , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2000 |
| País: | Brasil |
| Recursos: | Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo (FMVZ-USP) |
| Repositorio: | Brazilian Journal of Veterinary Research and Animal Science |
| Idioma: | portugués |
| OAI Identifier: | oai:revistas.usp.br:article/5808 |
| Acesso em linha: | https://www.revistas.usp.br/bjvras/article/view/5808 |
| Access Level: | acceso abierto |
| Palavra-chave: | Folículo ovariano FSH Gado Nelore Ultra-sonografia Ovarian follicle Nelore Ultrasonography |
| Resumo: | The objectives of this study were: (1) to determine the maximum diameter and the growth rate of the dominant follicle (DF) in Nelore cows; (2) to determine the interval between PGF2;µ; administration and the manifestation of estrus; (3) to investigate the influence of the DF removal on the number of corpora lutea (CL) and non-ovulated follicles (NOF) determined by ultrasonography (CLus and NOFus); and (4) to determine the progesterone (P4; ng/ml) and estradiol-17beta (E2; pg/ml) concentrations in Nelore cows submitted to superovulation with FSH. After ultrasonographic examinations on D0 (48 hours before the beginning of the superovulatory treatment), 42 Nelore donors were divided into three experimental groups: GI (without a DF, n = 15), GII (with a DF, n = 15), and GIII (with an aspirated DF, n = 12). Seven days after the first artificial insemination (D6) the number of CL and NOF was determined and the embryos collected (D13). Blood samples were collected on D0; D2; D4 (PGF2;µ; injection), D6 and D13. The results permit to conclude that although the maximum diameter and the growth rate of the DF were similar to those previously observed in European donors, in the Nelore breed it acts in a different manner on the ovarian follicular dynamic. |
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