def calc_energy_t1(forage_quality):
    """Look up energy content of forage given its forage quality, from IPCC 2006
    table 10.8."""

    quality_table = {  # IPCC 2006 table 10.8
        u'grain': 8.,
        u'high': 7.,
        u'moderate': 6.,
        u'low': 4.5,
    }
    MJ_per_kg_DM = quality_table[forage_quality]
    return MJ_per_kg_DM