Interferon tau secretion in cattle embryos in vitro fertilized before and after cryopreservation

The effect of cryopreservation in IFN-tau, from bovine embryos produced in vitro was evaluated. Two treated groups (G1= fresh bovine embryos, n=59 and G2= freezed embryos, n=84) were used to study the effect of cryopreservation on IFN-tau secretion. After reaching the blastocyst phase, the embryos were kept on individual culture for additional period of 7 days. On days 3 and 7 after the beginning of embryos cultivation, samples of the media culture were taken for IFN-tau secretion titration. Oocysts taken from follicles ranging from 3 to 5mm in diameter were obtained from ovaries of females at slaughterhouse. The embryos were frozen, after being dehydrated with ethylene glycol (1.8m), conditioned on 0.5ml palletes and frozen. Frozen embryos secreted lower IFN-tau than fresh embryos (P