Data/hora: 05/06/2024 18:16:41

Provedor de dados: 	96	
País: 	Brazil	
Título: 	Association of recombinant bovine somatotropin (rBST) with equine chorionic gonadotropin (eCG) on antral follicle count and oocyte production in Holstein and Tabapuã heifers	
Autores: 	Morais,Hévea de; Spuri,Renata; Gonçalves,Tarcísio de Moraes; Carvalho,Rafaela Rodrigues de; Andrade,Renato Campos; Pinto,Tássia Louregiani Carvalho; Souza,José Camisão de.	
Data: 	2012-12-01	
Ano: 	2012	
Palavras-chave: 	Embryo; Hormonal stimulation; Ovary.	
Resumo: 	The objective of this study was to investigate whether the use of rbST and eCG prior to ultrasound-guided follicular aspiration (OPU) improves oocyte yield and quality in Tabapuã and Holstein heifers. The study was conducted in two phases, 20 days apart, in a change-over design. The dominant follicle was ablated two days (D-2) before two treatments: stimulation (6 Holstein and 8 Tabapuã), 500 mg of rbST (Boostin®) on D0 and 500 IU of eCG (Folligon) on D2; and control (6 Holstein and 8 Tabapuã), in which heifers received injections of the excipient. Heifers were aspirated on D4. Oocytes were subjected to a well established commercial in vitro embryo production protocol (Vitrogen®) and embryos were evaluated seven days after fertilization. There was an effect from the interaction of treatment and breed, so that hormonal stimulation increased antral follicle count (2-8 mm) in Tabapuã (29.9±2.6 to 41.4±2.6), but not in Holstein heifers (14.4±2.6 to 15.5±2.6). Tabapuã heifers had higher mean antral follicle count than Holsteins (35.6±1.8 vs. 15.0±2.1). The number of viable oocytes was not increased by stimulation in Tabapuã (from 4.7±1.0 to 5.2±1.1 in control and simulation, respectively) or in Holstein heifers (1.3±1.9 to 2.0±1.6 in control and simulation, respectively). There was no difference in the percentage of heifers with more than five viable oocytes in the group treated (33 vs 27%). The number of blastocysts was not affected by treatment (1.75 vs. 1.00 in hormonal stimulation and control, respectively). The increase in antral follicle count in the stimulated Tabapuã heifers did not reflect upon oocyte yield. The differential breed response to the hormonal treatment underscores the need for additional tests, especially for the Holstein breed, in order to enhance OPU efficiency.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982012001200004	
Editor: 	Sociedade Brasileira de Zootecnia	
Relação: 	10.1590/S1516-35982012001200004	
Formato: 	text/html	
Fonte: 	Revista Brasileira de Zootecnia  v.41 n.12 2012	
Fonte: 	info:eu-repo/semantics/openAccess