Data/hora: 19/09/2024 21:13:09

Biblioteca(s): 	Embrapa Gado de Leite.	
Data corrente: 	25/03/2011	
Data da última atualização: 	11/08/2022	
Autoria: 	CAMARGO, L. S. de A.; FREITAS, C. de; SÁ, W. F. de; FERREIRA, A. de M.; SERAPIÃO, R. V.; VIANA, J. H. M.	
Afiliação: 	LUIZ SERGIO DE ALMEIDA CAMARGO, CNPGL; CELIO DE FREITAS, CNPGL; WANDERLEI FERREIRA DE SÁ, Pesquisador aposentado do CNPGL; ADEMIR DE MORAES FERREIRA, Pesquisador aposentado do CNPGL; RAQUEL VARELA SERAPIÃO, PESAGRO-RIO; JOAO HENRIQUE MOREIRA VIANA, CNPGL.	
Título: 	Gestation length, birth weigth and offspring gender ratio of in vitro-produced Gyr (Bos indicus) cattle embryos.	
Ano de publicação: 	2010	
Fonte/Imprenta: 	Animal Reproduction Science, v. 120, n. 1/4, p. 10-15, 2010.	
DOI: 	https://doi.org/10.1016/j.anireprosci.2010.02.013	
Idioma: 	Inglês	
Conteúdo: 	In vitro embryo production (IVP) has been suggested to result in a greater proportion of male calves, longer gestation and heavier offspring than artificial insemination in Bos taurus cattle. Despite the increasing use of IVP in tropical countries, its effects upon these traits in Bos indicus have not been conclusively investigated. Gyr is a B. indicus dairy breed with known physiological differences from B. taurus, such as a longer gestation period and lighter offspring. The aim of this study was to evaluate the effect of IVP on gestation length, birth weight and gender ratio in Gyr offspring. Oocytes were recovered from Gyr cows by ovum pick-up and were matured and fertilized with thawed Gyr semen in vitro. Embryos were cultured in CR2aa medium with cumulus cells and 10% fetal calf serum under 5% CO(2) at 38.5 degrees C in air. Seven- to eight-day blastocysts were transferred to synchronized recipients. Data on gestation length and birth weight of calves from in vitro-produced embryos were compared to data obtained from Gyr calves produced by artificial insemination (AI) and natural breeding (NB) during the same period using analysis of variance, and the gender ratio was compared to the expected 1:1 ratio using a chi-square test. IVP increased (P<0.01) the percentage of male offspring (76.9%) compared to the expected 1:1 ratio, while no difference (P>0.05) was observed in the AI and NB groups. Gestation length was similar (P>0.05) between the IVP and AI groups, but IVP-derived offspring were heavier (P<0.05) than AI- and NB-derived ones, mainly for male calves (P<0.05). These data show that in vitro production affects the subsequent development of Gyr embryos, resulting in a skewed sex ratio and increased birth weight.	
Palavras-Chave: 	Offspring.	
Thesagro: 	Bovino; Gado Zebu.	
Thesaurus Nal: 	cattle; in vitro fertilization.	
Categoria do assunto: 	L Ciência Animal e Produtos de Origem Animal	
Registro original: 	Embrapa Gado de Leite (CNPGL)	
Exemplares: 	CNPGL - (18197-1) - UPC - AP - DD -  -  -  - DIS