Variáveis morfométrica e hormonais ovariana e sanguínea de vacas Nelore submetidas a diferentes protocolos de IATF

• Autor(a) principal: Pereira, Jhonata Vieira Tavares do Nascimento
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5184
• topic: Bovino - Inseminação artificial; Bovino de corte; Fluído folicular; Sincronização do estro; Cattle - Artificial insemination; Beef cattle; Follicular fluid; Estrus synchronization; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA

This study was aimed to investigate the effects that different protocols for induction and synchronization of estrus and ovulation, with the use of eCG, BE, CE or GnRH associated with progestin could have on the follicle growth and pre-ovulatory follicle diameter. Furthermore the relationship with progesterone, LH, insulin, cortisol in the follicular fluid concentration and progesterone, cortisol, insulin serum concentrations of cows submitted to protocols. Ninety Nelore suckled cows were divided into six groups, 15 cows per protocol. The protocols consisted in the placement and removal of an intravaginal progesterone device (IPD) (0.75g of progesterone) in the first and eighth day respectively; application of prostaglandin (PGF2 &#61537;) on the eighth day, and except in protocol 1 was used estradiol benzoate (EB) on day 1. The other differences in the delineation of protocols were: Protocol 1 day 1 and day 8 (GnRH); Protocol 2 day 6 (PGF2 &#61537;), day 8 (PGF2 &#61537; + estradiol cypionate (EC)); Protocol 3 day 8 (eCG + EC); Protocol 4 day 8 (eCG + EB); Protocol 5 day 8 (eCG), day 9 (EB); Protocol 6 day 9 (EB). Overall 93.3% (84/90) of cows responded to synchronization protocol. However, it was observed that 28.9% of cows (26/90) did not have a synchronization of a new follicular wave, checked by the number of cows which have not developed a dominant follicle (5/26), cows with early ovulation (15/26) and cows that had a dominant follicle in regression process (6/26). There was no statistical difference in growth and diameter of the pre-ovulatory follicle between protocols. Progesterona, LH, insulina, cortisol concentrations on follicular fluid, as well as in cortisol and insulin serum concentration did nor differ with the protocols used. Although, in protocol 2, lower progesterone concentrations (P<0.05) were observed in the withdrawal of IPD. Twenty seven oocytes were recovered, which were classified according to quality: 1 (n=12), 2 (n=6), 3 (n=7) e 4 (n=2). The antecipation in the prostaglandin application in two days from IPD withdrawal result in lower progesterone concentrations.