  We present our preliminary results on the lowest moment <x> of quark
distribution functions of the pion using two flavor dynamical simulations with
Wilson twisted mass fermions at maximal twist. The calculation is done in a
range of pion masses from 300 to 500 MeV. A stochastic source method is used to
reduce inversions in calculating propagators. Finite volume effects at the
lowest quark mass are examined by using two different lattice volumes. Our
results show that we achieve statistical errors of only a few percent. We plan
to compute renormalization constants non-perturbatively and extend the
calculation to two more lattice spacings and to the nucleons.
