Tasa de preñez en búfalas sometidas a distintos protocolos de inseminación artificial a tiempo fijo en el nordeste argentino

Abstract

The objective of this trial was to compare the pregnancy rates obtained by two different protocols of fixed time artificial insemination (AIFT) in buffaloes of Mediterranean breed in the north of Corrientes, Argentina. Ninety three pluriparous buffaloes with calves, were used. Animals were divided in two groups. In Group 1 (G1, n=34) the protocol Ovsynch was rehearsed: synchronization (day 0): busereline 8 ug (GnRH); day 7: cloprostenol 150 mg (PGF2α); day 9: GnRH 8 ug; day 10: AIFT. Resynchronization (day 28: GnRH 8 ug); day 35: diagnostic of gestation by ultrasonography and PGF2α 150 ug to the animals diagnosed open; day 37: GnRH 8 ug; day 38: AIFT. In the Group 2 (G2, n=41) a protocol with intravaginal devices (DIV) of progestagens was used: synchronization (day 0): estradiol benzoate (BE) 2 mg and 1 DIV of first use during 7 days; day 7: PGF2α 150 mg; day 8: BE 1 mg; day 9: AIFT. Resynchronization (day 28): BE 1 mg and DIV of second use during 7 days; day 35: diagnostic of gestation by ultrasonography and PGF2α 150 ug to the animals diagnosed open; day 36: BE 1 mg; day 37: AIFT. Between days 55 and 75, cleanup bulls were used. On day 100 an echography was made to determine final pregnancy. Results for first insemination, resynchronization, and final pregnancy in G1 and G2 were respectively of 44 and 68% (p> 0.03), 75 and 80% and 83 and 87%. The highest pregnancy rate obtained by the group submitted to the progestagen intravaginal devices protocol, is emphasized.