  We present Herschel far-infrared (FIR) photometry of eleven quasars at
redshift z>5 that have previously been detected at 1.2mm. We perform full
spectral energy distribution (SED) fits over the wavelength range lambda_rest
~0.1-400mu for those objects with good Herschel detections. These fits reveal
the need for an additional far-infrared (FIR) component besides the emission
from a dusty AGN-powered torus. This additional FIR component has temperatures
of T_FIR ~ 40-60K with luminosities of L_(8-1000mu) ~ 10^13 L_sun (accounting
for 25-60% of the bolometric FIR luminosity). If the FIR dust emission is due
to star formation it would suggest star formation rates in excess of 1000 solar
masses per year. We show that at long wavelengths (lambda_rest > 50mu) the
contribution of the AGN-powered torus emission is negligible. This explains how
previous FIR studies of high-redshift quasars that relied on single component
fits to (ground-based) observations at lambda_obs > 350mu reached T_FIR and
L_FIR values similar to our complete SED fits. Stacking the Herschel data of
four individually undetected sources reveals a significant average signal in
the PACS bands but not in SPIRE. The average SED of sources with individual
Herschel detections shows a striking surplus in near- and mid-infrared emission
when compared to common AGN templates. The comparison between two average SEDs
(sources with and without individual Herschel detections) matched in the
UV/optical indicates that for these objects the strength of the MIR emission
may correlate with the strength of the FIR emission.
