VIABILIDADE DE EMBRIÕES BOVINOS PRODUZIDOS IN VITRO TRANSPORTADOS POR DIFERENTES TEMPOS EM MEIO DE MANUTENÇÃO COM ANTIOXIDANTES

Abstract

The antioxidants use such as melatonin and resveratrol has shown beneficial effects in the embryos in vitro production, reducing reactive oxygen species and improving embryo quality and development. The objective of this study was to evaluate the addition effect of the antioxidants resveratrol and melatonin to the maintenance medium on the viability of bovine embryos produced in vitro, maintained at 36ºC in different transport simulation times. On the seventh day (D7) of in vitro culture, embryos of stage I and II in the initial blastocyst stage (B1), blastocyst (B1) and expanded blastocyst (B1) were randomly assigned to three maintenance conditions: control medium (maintenance medium + 10-9M melatonin) and resveratrol (maintenance medium + 0.5μM resveratrol). To simulate the transport, the embryo vanes were placed in embryo carrier at a temperature of 36°C and maintained for 6, 9 and 12 hours. After the time determined according to the treatment, the embryos were removed and regrowth in culture medium for 72 hours for quality evaluation and embryonic development. The experiment was carried out in a completely randomized design with factorial arrangement 3x3. Statistical analyzes were performed using the R Project softwareversion 3.5.0 with a significance level of 5% probability. Initially analyzes were carried out by ordinal multinomial data, to evaluate the treatments in a factorial arrangement. In a second process, nine treatments were considered for the isolated evaluation, performing chi-square tests. With 72 hours of regrowth, no difference was observed between treatments in the embryos percentage that developed, degenerated and hatched. The development and embryonic quality were not affected by the mean and time of transport simulation. Embryos packed in the Bx stage showed higher hatch rates and lower degeneration rates. It is concluded that it is feasible to transport fresh bovine embryos, produced in vitro, in maintenance medium without supplementation of the studied antioxidants for 12 hours in carrier at 36ºC. Embryos packed in stage Bx, regardless of transport simulation time, showed greater viability.