What was O’Brien’s job before going to the war?

From the text:

I spent the summer of 1968 working in an Armour meatpacking plant in my hometown of Worthington, Minnesota. The plant specialized in pork products, and for eight hours a day I stood on a quarter-mile assembly line—more properly, a disassembly line—removing blood clots from the necks of dead pigs. My job title, I believe, was Declotter.