Data/hora: 13/06/2024 11:18:22

Biblioteca(s): 	Embrapa Caprinos e Ovinos.	
Data corrente: 	09/06/2016	
Data da última atualização: 	23/08/2017	
Autoria: 	BALARO, M. F. A.; FONSECA, J. F. da; BARBOSA, T. G. B.; SOUZA-FABJAN, J. M. G.; FIGUEIRA, L. M.; TEIXEIRA, T. A.; CARVALHEIRA, L. R.; BRANDÃO, F. Z.	
Afiliação: 	Department of Pathology and Veterinary Clinic, Veterinary School, Fluminense Federal University (UFF) - Niteroi, RJ, Brazil; JEFERSON FERREIRA DA FONSECA, CNPC; Department of Pathology and Veterinary Clinic, Veterinary School, Fluminense Federal University (UFF) - Niteroi, RJ, Brazil; Department of Pathology and Veterinary Clinic, Veterinary School, Fluminense Federal University (UFF) - Niteroi, RJ, Brazil; Department of Animal Science, Veterinary School, Fluminense Federal University (UFF) - Niteroi, RJ, Brazil; Department of Pathology and Veterinary Clinic, Veterinary School, Fluminense Federal University (UFF) - Niteroi, RJ, Brazil; Department of Pathology and Veterinary Clinic, Veterinary School, Fluminense Federal University (UFF) - Niteroi, RJ, Brazil; Department of Pathology and Veterinary Clinic, Veterinary School, Fluminense Federal University (UFF) - Niteroi, RJ, Brazil.	
Título: 	Potential role for GnRH in the synchronization of follicular emergence before the superovulatory Day 0 protocol.	
Ano de publicação: 	2016	
Fonte/Imprenta: 	Domestic Animal Endocrinology, Stoneham, v. 54, p. 10-14, Jan. 2016.	
DOI: 	10.1016/j.domaniend.2015.07.002	
Idioma: 	Inglês	
Conteúdo: 	Abstract: The ability of gonadotropin-releasing hormone (GnRH) to synchronize ovulation and new follicular wave emergence before a "superovulatory Day 0" protocol was assessed in Santa Inês ewes. For estrus synchronization, a 60-mg medroxyprogesterone acetate sponge was inserted for 6 d. One day before sponge removal, 37.5-ug d-cloprostenol and 300 IU equine chorionic gonadotropin were injected intramuscularly (i.m.). After sponge removal, ewes were assigned to the following 3 groups: (1) GC-1 mL saline at 12 h (n = 10); (2) G24h-0.025-mg lecirelin (GnRH agonist) i.m. at 24 h (n = 10); or (3) G36h-0.025-mg lecirelin i.m. at 36 h (n = 9). Ovarian ultrasonography was conducted to assess follicular dynamics. Blood was collected to determine plasma concentrations of progesterone and estradiol. Females from G36h and GC had a greater (P < 0.05) estrous response than those from the G24h group (78.0 and 90.0 vs 0.0%, respectively). Ewes from G24h and G36h had earlier (P < 0.05) ovulation (48.0 ± 10.2 and 56.7 ± 5.7 h) compared with those from Gc (64.1 ± 9.7 h). The mean number of ovulations per ewe was greater (P < 0.05) in Gc (1.9 ± 0.6) and G36h (2.0 ± 1.0) than G24h (1.2 ± 0.4). Plasma concentrations of progesterone and estradiol differed over time. Follicular growth during the postovulatory day was affected (P < 0.05) by day of the estrus cycle as well as by the interaction (P < 0.05) of treatment and day of the estrus cycle. There was a larger (P < 0.05) population of medium follicles during the first 24 h after the ovulation in G24h compared with Gc, and there was an absence of large follicles in G36h between 36 and 72 h after ovulation. In conclusion, the use of GnRH agonist at 36 h more efficiently synchronized ovulation and promoted the absence of dominant follicles during early diestrus and may be used at the start of superovulatory treatment at 80 h in Santa Inês ewes.	
Palavras-Chave: 	GnRH; Medroxyprogesterone acetate; MOET; Oestrus synchronization; Raça Santa Inês.	
Thesagro: 	Ciclo estral; Estradiol; Hormônio animal; Ovino; Ovulação; Progesterona; Sincronização do cio.	
Thesaurus Nal: 	Ovarian follicles; Ovulation; Progesterone; Sheep; Ultrasonography.	
Categoria do assunto: 	L Ciência Animal e Produtos de Origem Animal	
Registro original: 	Embrapa Caprinos e Ovinos (CNPC)	
Exemplares: 	CNPC - (31104-1) - UPC - AP - DD -  -  -  - DIS