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

Autor: Joanna Maria Gonçalves Souza-Fabjan, M. E. F. Oliveira, E. K. N. Arashiro, L. R. Côrtes, A. L. R. S. Maia, J. F. Fonseca, B.B. Martins, D.S. Dias, Felipe Zandonadi Brandão, M.O. Veiga, Pawel M. Bartlewski
Přispěvatelé: Universidade Federal Fluminense (UFF), Univ Grande Rio, Univ Presidente Antonio Carlos, Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA), Universidade Estadual Paulista (Unesp), Univ Guelph
Rok vydání: 2020
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Zdroj: Web of Science
Repositório Institucional da UNESP
Universidade Estadual Paulista (UNESP)
instacron:UNESP
ISSN: 1879-0054
Popis: Made available in DSpace on 2021-06-25T12:28:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) EMBRAPA Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) 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 mg 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 similar to 47% of all hCG-treated does, and significantly increased the pregnancy rate in estrous-induced Toggenburg goats in the transition to the breeding season. (C) 2020 Elsevier Inc. All rights reserved. Univ Fed Fluminense, Fac Vet, Rua Vital Brasil Filho 64, Niteroi, RJ, Brazil Univ Grande Rio, Fac Med Vet, Rua Prof Jose de Souza Herdy 1160, Duque De Caxias, RJ, Brazil Univ Presidente Antonio Carlos, Av Juiz de Fora 1100, Juiz De Fora, MG, Brazil Embrapa Caprinos & Ovinos, Rodovia MG 133,Km 42, Coronel Pacheco, MG, Brazil Sao Paulo State Univ, Dept Prevent Vet Med & Anim Reprod, Via Acesso Prof Paulo Donato Castelane S-N, Jaboticabal, SP, Brazil Univ Guelph, Ontario Vet Coll, Dept Biomed Sci, Guelph, ON N1G 2W1, Canada Sao Paulo State Univ, Dept Prevent Vet Med & Anim Reprod, Via Acesso Prof Paulo Donato Castelane S-N, Jaboticabal, SP, Brazil CNPq: 314952/2018-7 EMBRAPA: 20.19.01.004.00.03.001 FAPEMIG: CVZPPM-000201-17
Databáze: OpenAIRE
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