Aplicação de PGF2α no momento da inseminação artificial em tempo fixo em vacas mestiças de corte

Abstract

The artificial insemination at time fixed (TAI) is characterized as a biotechnology of reproduction that realize synchronized estrous cycle through in hormones treatments and has an objective predict the moment of ovulation of females making possible an artificial insemination (AI) without a detection of estrus. With an objective to elevate the rate of conception in bovine herds it is propose an application the GnRH or PGF2α at TAI. Currently, the increase in conception rate it is evident when has the application of PGF2α at TAI in cows treated with PGF2α and GnRH based protocols, however, there are not conclusive reports that there is an increase in conception rate for cows that submitted to a protocol based on progesterone (P4) and estradiol benzoate (BE). In this study, 326 bovine females were selected to be submitted to the TAI protocol. The cows were separated into 2 groups: Group 1 - control (n = 163), the day of the TAI the cows received an application of 2 mL of placebo solution and the Group 2 - PGF (n = 163), the day of TAI was treated with 10 mg (2 mL) of dinoprost tromethamine. In general, the conception rate was similar (P> 0.05) between the females of the treated and non-PGF2α treated groups at the time of the TAI. This result suggests that females treated at the time of TAI were not influenced by PGF2α functions at this time, as an increase in the synchronization rate at the end of the protocol, both by induction of complete luteolysis and by the auxiliary stimulus in the ovulation mechanism.