  We calculate the temperature dependence of the transport properties of
heavy-fermion systems such as resistivity, optical conductivity, thermoelectric
power, the electronic part of the thermal conductivity, and the "figure of
merit." The one-particle properties of the periodic Anderson model are obtained
within dynamical mean-field theory for the paramagnetic phase using Wilson's
numerical renormalization group and the modified perturbation theory as
impurity solvers. We discuss the dependence of the transport properties on the
band filling, valence, and Coulomb correlation $U$. The typical experimental
findings can be reproduced and understood, in particular the temperature
dependence of the resistance and the thermoelectric power and their absolute
magnitude for both metallic heavy-fermion systems and Kondo insulators. For
large values of $U$, we find a negative Seebeck coefficient $S(T)$ for an
intermediate-temperature regime as observed in $S(T)$ of CeCu$_2$Si$_2$. We
analyze different estimates for possible characteristic low-temperature scales
of the lattice. Our results indicate a one-parameter scaling of thermodynamic
and some transport properties with a strongly occupancy-dependent scaling
function. This is consistent with a strong-coupling local Fermi-liquid fixed
point of the effective site governing all low-lying excitations for $T\to 0$ in
the paramagnetic phase.
