Data/hora: 21/06/2024 10:31:36

Biblioteca(s): 	Embrapa Gado de Leite.	
Data corrente: 	10/10/2005	
Data da última atualização: 	11/08/2022	
Autoria: 	CAMARGO, L. S. de A.; VIANA, J. H. M.; SÁ, W. F. de; FERREIRA, A. M.; VALE FILHO, V. R.	
Afiliação: 	LUIZ SERGIO DE ALMEIDA CAMARGO, CNPGL.	
Título: 	Developmental competence of oocytes from prepubertal Bos indicus crossbred cattle.	
Ano de publicação: 	2005	
Fonte/Imprenta: 	Animal Reproduction Science, v. 85, n. 1/2, p. 53-59, 2005.	
DOI: 	https://doi.org/10.1016/j.anireprosci.2004.04.020	
Idioma: 	Inglês	
Conteúdo: 	The aim of the present study was to evaluate the effect of age on embryogenic competence of oocytes recovered from Bos indicus crossbred calves and heifers. Cumulus-oocyte complexes (COCs) were collected from 4- to 7-month-old calves (experiment 1) and from 9- to 14-month-old heifers (experiment 2) during processing at an abattoir. In both experiments cow COCs were used as control. COCs were in vitro matured and fertilized, and the presumptive zygotes co-cultured with cumulus cells until 224 h post insemination (hpi). In experiment 1, the development rate during the first 68-72 hpi was similar (P > 0.05) between embryos derived from calves and cows. Fewer embryos from calves developed to the blastocyst stage, resulting in a lesser blastocyst production as well as lesser hatching rate (P < 0.05). The embryo development after blastocyst stage was, nevertheless, similar (P > 0.05) between blastocysts derived from calves and cows, suggesting that the development after blastocoele formation is not compromised in embryos derived from calves. In experiment 2, there were no differences (P > 0.05) on cleavage, blastocyst and hatching rates between embryos derived from prepubertal heifers and cows. The rate of blastocyst development until hatching was also similar (P > 0.05). These results indicate that oocytes from 9- to 14-month-old B. indicus crossbred heifers have the same developmental competence as oocytes derived from cows, while ocytes derived from 4- to 7-month-old B. indicus crossbred calves are less competent in developing to the blastocyst stage in vitro. It suggests that oocyte competence in B. indicus crossbred cattle is achieved around 9-14 months of age.	
Palavras-Chave: 	Fertilização in vitro; Oocitos.	
Thesagro: 	Bovino.	
Categoria do assunto: 	L Ciência Animal e Produtos de Origem Animal	
Registro original: 	Embrapa Gado de Leite (CNPGL)	
Exemplares: 	CNPGL - (14538-1) - UPC - AP - DD -  -  -  - DIS