It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that once roasted meat of the shoulder was presented to the Prophet (peace and blessings be upon him). The Prophet (peace and blessings be upon him) ate it and then performed prayer without making a fresh ablution.
Hadith Referenceمسند احمد / ومن مسند بني هاشم / 3295