Dinâmica folicular, função luteal e momento da ovulação em protocolos de IATF em bubalinos (Bubalus bubalis)

Abstract

In order to evaluate the effects of eCG, BE and GnRH on follicular dynamics and luteal characteristics of buffaloes (Bubalus bubalis) on ovulation synchronization programs, 40 females were submitted to different FTAI protocols. At day 0 all the animals received an intravaginal device of P4 1.0g, associated to 2mg of BE and 0,5mg of the cloprostenol sodium. In D9, implant withdrawals occurred and 0.5mg of sodium cloprostenol was administered in all animals and 400UI of eCG in half of the buffaloes. In D10 (24 hours after implant removal) half of the eCG-treated females and half of the non-eCG-treated females received 1.0 mg of BE. In D11 the other half of the eCG treated females and the untreated females received 10μg of a GnRH (buserelin acetate) analogue. Thus, the four experimental groups were: C/eGC+GnRH (n = 10), S/eGC+GnRH (n= 10), C/eCG+BE (n= 10) and S/eCG+BE (n= 10). The follicular characteristics of DFol (D9, D10 and D11), DFOV, TXFol, VFOV, %VFOV and MOV in follicular dynamics were evaluated using B-mode and Power-Doppler ultrasonography, as well as the DCLD18, %VCL and dosages of P4D18 for the luteal function. Statistical analyzes were performed using the Tukey test, Kruskal-Wallis test and repeated measures ANOVA with a significance level of 5%. There was no significant difference between the treatments of IATF C/eCG or S/eCG, associated to GnRH or BE as inductors of ovulation, for none of the follicular characteristics evaluated during moments of the dynamics. Significant statistical differences were found for DCLD18 with 1.78±0.12 cm in the C/eCG+BE group and 1.62±0.11 cm in the S/eCG+BE group (P = 0.047), as well as in the P4 between treatments C/eCG+GnRH (4.09±0.94 ng/mL) and S/eGC+GnRH (2.80±0.70 ng/mL), P = 0.017. Regarding the variables evaluated by Power-Doppler mode, no statistical difference between the experimental groups was verified. It was concluded that the use of eCG associated with BE or GnRH enabled efficient synchronization and induction of ovulation in lactating buffaloes submitted to an FTAI protocol, and it should also be taken into account the cost / benefit factor that favored the use of BE as ovulation inducer.