  We present results of a new feedback scheme implemented in the Munich galaxy
formation model. The new scheme includes a dynamical treatment of galactic
winds powered by supernovae explosions and stellar winds in a cosmological
context. We find that such a scheme is a good alternative to
empirically-motivated recipes for feedback in galaxy formation. Model results
are in good agreement with the observed luminosity functions and stellar mass
function for galaxies in the local Universe. In particular, the new scheme
predicts a number density of dwarfs that is lower than in previous models. This
is a consequence of a new feature of the model, that allows an estimate of the
amount of mass and metals that haloes can permanently deposit into the IGM.
This loss of material leads to the suppression of star formation in small
haloes and therefore to the decrease in the number density of dwarf galaxies.
The model is able to reproduce the observed mass-stellar metallicity and
luminosity-gas metallicity relationships. This demonstrates that our scheme
provides a significant improvement in the treatment of the feedback in dwarf
galaxies. Despite these successes, our model does not reproduce the observed
bimodality in galaxy colours and predicts a larger number of bright galaxies
than observed. Finally, we investigate the efficiency of metal injection in
winds and in the intergalactic medium. We find that galaxies that reside in
haloes with M_vir < 10^12 M_sun/h may deposit most of their metal mass into the
intergalactic medium, while groups and clusters at z=0 have lost at most a few
percent of their metals before the bulk of the halo mass was accreted.
