  Spectroscopic observations of hot stars belonging to the young cluster
LMC-NGC 2004 and its surrounding region were carried out with the VLT-GIRAFFE
facilities in MEDUSA mode. We determine fundamental parameters (Teff, logg,
vsini, and radial velocity), for all B and Be stars in the sample thanks to a
code developed in our group. The effect of fast rotation (stellar flattening
and gravitational darkening) are taken into account in this study. We also
determine the age of observed clusters. We compare the mean vsini obtained for
field and cluster B and Be stars in the Large Magellanic Cloud (LMC) with the
ones in the Milky Way (MW). We find, in particular, that Be stars rotate faster
in the LMC than in the MW, in the field as well as in clusters. We discuss the
relations between vsini, metallicity, star formation conditions and stellar
evolution by comparing the LMC with the MW. We conclude that Be stars begin
their Main Sequence life with an initial rotational velocity greater than the
one of B stars. It is probable that only part of the B stars, with a sufficient
initial rotational velocity, can become Be stars. This result may explain the
differences in the proportion of Be stars in clusters with similar ages.
