One thousand miles south of the eastern Iowa bunkhouse where dozens of mentally retarded men once lived is the original Texas headquarters of their employer, Henry's Turkey Service…Since February, when state and federal officials swarmed the Atalissa bunkhouse and evacuated its 21 remaining workers, Henry's has ceased all operations. …the company housed as many as 60 mentally retarded men in a crumbling old schoolhouse in Atalissa, waking them at 2:30 a.m. to work in a meat-processing plant for as little as $65 per month…