  Dynamical 2+1 flavour lattice QCD is used to calculate the splittings between
the masses of mesons and baryons containing a single static heavy quark and
domain-wall light and strange quarks. Our calculations are based on the
dynamical domain-wall gauge field configurations generated by the RBC and UKQCD
collaborations at a spatial volume of (2.7 fm)^3 and a range of quark masses
with a lightest value corresponding to a (partially-quenched) pion mass of 275
MeV. When extrapolated to the physical values of the light quark masses, the
results of our calculations are generally in good agreement with experimental
determinations in the bottom sector. However, the static limit splittings
between the Omega_b^- baryon and other bottom hadrons tend to slightly
underestimate those obtained using the recent D-zero measurement of the
Omega_b^-.
