Data/hora: 22/06/2024 19:06:15

Biblioteca(s): 	Embrapa Caprinos e Ovinos.	
Data corrente: 	12/01/2021	
Data da última atualização: 	03/08/2021	
Autoria: 	CÔRTES, L. R.; SOUZA-FABJAN, J. M. G.; DIAS, D. S.; MARTINS, B. B.; MAIA, A. L. R. S.; VEIGA, M. O.; ARASHIRO, E. K. N.; BRANDÃO, F. Z.; OLIVEIRA, M. E. F.; BARTLEWSKI, P. M.; FONSECA, J. F. da.	
Afiliação: 	JEFERSON FERREIRA DA FONSECA, CNPC.	
Título: 	Administration of a single dose of 300 IU of human chorionic gonadotropin seven days after the onset of estrus improves pregnancy rate in dairy goats by an unknown mechanism.	
Ano de publicação: 	2021	
Fonte/Imprenta: 	Domestic Animal Endocrinology, v. 74, e106579, 2021.	
DOI: 	10.1016/j.domaniend.2020.106579	
Idioma: 	Inglês	
Conteúdo: 	Abstract: This study examined the effects of exogenous hCG administration on ovarian function and pregnancy rates in estrous-induced dairy goats during the transition into the breeding season. Eighty-six Toggenburg does received 60 mg of medroxyprogesterone acetate intravaginal sponge for 6 d plus 200 IU of equine chorionic gonadotropin and 30 ?g of d-cloprostenol i.m. 24 h before sponge removal, and were then bred for 96 h. Seven days (D7) after first mating the does received either 1 mL of saline (the control group, n = 43) or 300 IU of hCG (the hCG-treated group, n = 43) i.m. Transrectal ovarian ultrasonography (B-mode and color Doppler) was performed on D7, D13, D17, and D21 and ultrasonographic pregnancy detection on D30. Pregnancy rate was higher (P < 0.05) in hCG-treated goats (90.7%; 39/43) than that in control animals (74.4%; 32/43). Accessory luteal structures (ALSs) were detected in 46.5% (20/43) of hCG-treated does. All hCG-treated does that had ALSs and 82.6% of goats without ALS post-treatment remained pregnant. The total luteal area increased (P < 0.05) from D7 to D13 in pregnant animals of both groups, whereas mean vascular area declined (P < 0.05) by D21 in all nonpregnant does. Serum progesterone concentrations increased (P < 0.05) on D21 in pregnant goats of both groups, but they were related to changes in luteal tissue content only in control does throughout the present study. Mean daily numbers of small- and medium-sized antral follicles decreased (P < 0.05) only in pregnant animals of both groups with a decline in medium follicle numbers occurring earlier in hCG-treated (D13) compared with control does (D17). To summarize, a single dose of hCG given on D7 after estrus was followed by a decrease in the number of medium-sized antral follicles in gestating hCG-treated does, induced the formation of ALSs in ~47% of all hCG-treated does, and significantly increased the pregnancy rate in estrous-induced Toggenburg goats in the transition to the breeding season.	
Palavras-Chave: 	Biotecnologia da reprodução; HCG; Ovary; Taxa de prenhez.	
Thesagro: 	Cabra Leiteira; Caprino; Progesterona; Reprodução Animal; Sincronização do Cio; Ultrassom.	
Thesaurus Nal: 	Anestrus; Dairy goats; Estrous cycle; Human chorionic gonadotropin; Progesterone; Small ruminants; Toggenburg; Ultrasonography.	
Categoria do assunto: 	L Ciência Animal e Produtos de Origem Animal	
Registro original: 	Embrapa Caprinos e Ovinos (CNPC)	
Exemplares: 	CNPC - (39740-1) - UPC - AP - DD -  -  -  - DIS