You can find it in 'GDB_Items' table.
<metadata xml:lang="en"><eainfo><detailed><enttyp><enttypl>Export_Output</enttypl></enttyp><attr><attrlabl>OBJECTID</attrlabl><attrdef>Internal feature number.</attrdef><attrdefs>Esri</attrdefs><attrdomv><udom>Sequential unique whole numbers that are automatically