  We have performed point contact spectroscopy measurements on a sample
constituted by a metallic ferromagnetic oxide (SrRuO_3) bottom electrode and a
tunnel ferrimagnetic (CoFe_2O_4) barrier. Andreev reflection is observed across
the tunnel barrier. From the comparison of Andreev reflection in SrRuO3 and
across the CoFe_2O_4 barrier we infer that the ferrimagnetic barrier has a spin
filter efficiency not larger than +13%. The observation of a moderate and
positive spin filtering is discussed in the context of the microstructure of
the barriers and symmetry-related spin filtering effects.
