  We consider the production of heavy ($b,t$) quark pairs at proton colliders
in the theoretical framework of the MSSM. Under the assumption of a
"moderately" light SUSY scenario, we first compute the leading logarithmic MSSM
contributions at one loop for the elementary processes of production from a
quark and from a gluon pair in the 1 TeV c.m. energy region. We show that in
the initial gluon pair case (dominant in the chosen situation at LHC energies)
the electroweak and the strong SUSY contributions concur to produce an enhanced
effect whose relative value in the cross sections could reach the twenty
percent size for large $\tan\beta$ values in the realistic proton-proton LHC
process.
