Resumo
O objetivo desse trabalho foi determinar a eficiencia do cipionato de estradiol (CE) como indutor de ovulacao em um protocolo de inseminacao artificial de tempo fixo, em bufalas criadas, de forma extensiva, em areas de varzea de Itacoatiara, Amazonas, Brasil. Um total de 69 vacas bufalas mesticas foram selecionadas e divididas em dois lotes. No primeiro lote 39 bufalas receberam um dispositivo intravaginal de progesterona (P4; 1,0g) novo e 2,0mg im de BE, no D0. No D9 o dispositivo intravaginal de P4 foi removido e foram aplicados 0,53mg im de PGF2 e 400UI im de eCG. De forma aleatoria as bufalas foram divididas em dois grupos: o GCE (20 vacas) que recebeu 1mg de CE no D9, e o grupo GBE (19 vacas) que recebeu 1mg de BE 24h apos, no D10. No D11 todas a bufalas foram submetidas a IATF 56h apos a retirada do implante intravaginal de P4. A mesma metodologia foi utilizada no segundo lote, onde 30 bufalas foram divididas em GCE (14 vacas) e GBE (16 vacas). Para avaliacao da dinamica folicular, o diametro do maior foliculo no ovario de 11 bufalas por tratamento foi avaliado no D0 e D9 ao D12 (intervalo de 24 horas) por ultrassonografia. Todos os animais do experimento foram submetidos a ultrassonografia para diagnostico de gestacao com mais de 30 dias apos a inseminacao artificial. Nao houve diferenca (P>0,05) no diametro folicular (9,6 ± 0,89mm vs. 10,7 ± 1,12mm; P = 0,06), na taxa de ovulacao (90,9% vs. 90,9%; P = 1) e taxa de prenhez (58,8% vs. 62,9%; P = 0,79), no entanto, bufalas do tratamento GCE apresentam menor tempo entre a remocao da P4 e a ovulacao quando comparado com as bufalas do GBE (37,4h vs. 52,8h; P=0,001), respectivamente. Conclui-se que a implantacao da IATF nas varzeas do Amazonas e viavel e que utilizacao do CE no dia da retirada do implante intravaginal de P4 resulta em respostas semelhantes ao BE, sendo mais vantajoso visto que reduz o numero de manejos e os gastos com a mao de obra.
The objective of this study was to determine the efficiency of estradiol cypionate (CE) as an ovulation inducer in a fixed-time artificial insemination protocol in buffaloes managed in floodplain areas of Itacoatiara, Amazonas, Brazil. A total of 69 crossbred buffalo cows were selected and distributed into two allotments. In the first allotment, 39 females received a new progesterone intravaginal device (P4; 1.0g) and 2.0mg im of BE, on D0. On D9 the intravaginal device of P4 was removed and 0.53mg im of PGF2 and 400UI im of eCG were applied. The buffaloes were randomly divided into two groups: the GCE (20 cows) that received 1mg of EC on D9, and the GBE group (19 cows) that received 1mg of BE 24h later, on D10. In D11, all females were submitted to IATF 56h after the removal of the intravaginal P4 implant. The same methodology was used in the second allotment, where 30 females were distributed into GCE (14 cows) and GBE (16 cows). To assess follicular dynamics, the diameter of the largest follicle in the ovary of 11 buffaloes per treatment was evaluated at D0 and D9 at D12 (24-hour interval) by ultrasound. All animals in the experiment were submitted to ultrasound to diagnose pregnancy more than 30 days after artificial insemination. There was no difference (p>0.05) in follicular diameter (9.6 ± 0.89mm vs. 10.7 ± 1.12mm; p = 0.06), in the ovulation rate (90.9% vs. 90, 9%; P = 1) and pregnancy rate (58.8% vs. 62.9%; p = 0.79), however, buffaloes from the GCE treatment have less time between P4 removal and ovulation when compared to GBE buffaloes (37.4h vs. 52.8h; P = 0.001), respectively. Thus, it was concluded that the implantation of the IATF in the Amazon floodplains is feasible and that the use of the EC on the day of removal of the P4 intravaginal implant results in responses similar to the BE, being more advantageous since it reduces the number of managements and the expenses with the labor.