Descrição
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)
EMBRAPA
Coordenacno de Aperfeicoamento de Pessoal de Nivel Superior-Brasil
This study was conducted to assess effects of two hormonal treatments on ovarian follicular status, estrous synchrony and fertility in dairy goats during the non-breeding season when duration of progestogen device use varied by 12 h. In both experiments, does were administered 60 mg of medmxyprogesterone acetate via intravaginal devices, respectively, for 6 and 6.5 d (G6 and G6.5). At 24 or 36 h before device removal, 200 IU of eCG im and 30 mu g d-clopmstenol im were administered. In Experiment 1 (n = 24), data related to sexual behavior and that were collected using ovarian ultrasonography were recorded, and in Experiment 2 (n = 83) fertility was assessed after Flexible Time Artificial Insemination (FxTAI). The interval from device removal to estrus was shorter (P < 0.05) after imposing the G6.5 treatment regimen. Diameter of largest and second-largest ovarian follicles and interval from device removal to ovulation were similar (P> 0.05) between groups. The does treated with the G6.5 hormonal regimen had greater estrous synchrony, associated with greater development of largest follicles at the time of device removal, which might have led to a lesser fertility rate (P > 0.05). Conversely, treatment with the G6 hormonal regimen resulted in a greater conception rate. In conclusion, increasing time the intravaginal device is inserted from 6 to 6.5 d resulted in greater estrous synchrony, advanced ovarian follicular development, abnormal CL function and lesser pregnancy rates in artificially inseminated dairy goats when there were treatments during the non-breeding season.
Univ Fed Fluminense, Fac Vet, Av Vital Brazil Filho 64, BR-24230340 Niteroi, RJ, Brazil
Univ Estadual Paulista, Fac Ciencias Agr & Vet, Via Acesso Prof Paulo Donato Castellane S-N, BR-14884900 Jaboticabal, SP, Brazil
Univ Fed Vicosa, Av Peter Henry Rolfs S-N, BR-36570000 Vicosa, MG, Brazil
Embrapa Gado Leite, Rua Eugenio do Nascimento 610, BR-36038330 Juiz De Fora, MG, Brazil
Embrapa Caprinos & Ovinos, Estr Sobral Groairas,Km 04,CP 145, BR-62010970 Sobral, CE, Brazil
Univ Estadual Paulista, Fac Ciencias Agr & Vet, Via Acesso Prof Paulo Donato Castellane S-N, BR-14884900 Jaboticabal, SP, Brazil
CNPq: 310166/2012-8
CNPq: 479826 2013-7
FAPEMIG: CVZ-PPM 00201-17
EMBRAPA: 20.19.01.004.00.03.001
Coordenacno de Aperfeicoamento de Pessoal de Nivel Superior-Brasil: 001