Data/hora: 07/06/2024 08:07:40

Biblioteca(s): 	Embrapa Caprinos e Ovinos; Embrapa Gado de Leite.	
Data corrente: 	21/05/2010	
Data da última atualização: 	15/02/2024	
Autoria: 	VIANA, J. H. M.; PALHÃO, M. P.; SIQUEIRA, L. G. B.; FONSECA, J. F. da; CAMARGO, L. S. de A.	
Afiliação: 	JOAO HENRIQUE MOREIRA VIANA, CNPGL; M. P. PALHÃO, UFV; LUIZ GUSTAVO BRUNO SIQUEIRA, CNPGL; JEFERSON FERREIRA DA FONSECA, CNPC; LUIZ SERGIO DE ALMEIDA CAMARGO, CNPGL.	
Título: 	Ovarian follicular dynamics, follicle deviation, and oocyte yield in Gyr breed (Bos indicus) cows undergoing repeated ovum pick-up.	
Ano de publicação: 	2010	
Fonte/Imprenta: 	Theriogenology, v. 73, n. 7, p. 966-972, 2010.	
DOI: 	https://doi.org/10.1016/j.theriogenology.2009.11.025	
Idioma: 	Inglês	
Conteúdo: 	The objective of this study was to evaluate ovarian follicular dynamics during intervals between successive ovum pick-up (OPU) and determine its effects on the number and quality of recovered cumulus-oocyte complexes (COCs) in Zebu cows (Bos indicus). Pluriparous nonlactating Gyr cows (Bos indicus; n = 10) underwent four consecutive OPU sessions at 96-h intervals. The dynamics of ovarian follicular growth between OPU sessions was monitored by twice-daily ultrasonographic examinations. A single dominant follicle (DF) or two codominant (CDF) follicles (>9 mm) were present in 63.3% (19 of 30) of intervals studied, with follicle deviation beginning when the future dominant follicle (F1) achieved a diameter of 6.2 0.3 mm. The phenomenon of codominance was observed in four (13.3%) of the inter-OPU intervals. The remaining intervals (36.6%, 11 of 30) were characterized by a greater follicular population, lower rate of follicular growth, and a smaller diameter F1 (P < 0.0001). There was a tendency (P = 0.08) toward an increase in the number of recovered COCs when dominant follicles were not present (NDF). The quality of COCs was not affected by the presence of a single dominant follicle, but codominant follicles resulted in recovery of a lower proportion of viable embryos (40.0%, 62.1%, and 63.6%; P < 0.05) and higher proportions of degenerate COCs (56.0%, 30.3%, and 28.6%; P < 0.05) for CDF, NDF, and DF respectively.We concluded that, in Zebu cows, (a) repeated follicle spirations altered ovarian follicular dynamics, perhaps by increasing follicular growth rate; (b) follicular dominance could be established in cows undergoing twice-a-week OPU; and (c) the presence of a dominant follicle during short inter-OPU intervals may not affect COC quality, except when a codominant follicle was present. # 2010 Elsevier Inc. All rights reserved.	
Palavras-Chave: 	Brasil; Dinâmica folicular; Folículo; Follicle ablation; OPU; Ovarian follicle; Ovarian follicular development; Zebu cattle.	
Thesagro: 	Ciclo estral; Endocrinologia; Gado; Reprodução animal.	
Categoria do assunto: 	L Ciência Animal e Produtos de Origem Animal	
Registro original: 	Embrapa Gado de Leite (CNPGL)	
Exemplares: 	CNPC - (23152-1) - UPC - AP - DD -  -  -  - DIS
CNPGL - (18200-1) - UPC - AP - DD -  -  -  - DIS