Ethnographically, ''fecal free'' is a lexical marker that invokes a form of industrialized swine husbandry used in large-scale confinement hog production. Using participant observation and interview research with Illinois contract hog producers, I explore the basis of this husbandry in the biological fragility of confinement hogs. Rather than biology being a simplistic ''state of nature,'' as it was in early neo-Marxist and populist studies of the 1970s, the frailty of confinement hogs suggests that industrial hog biology is a socially constructed state that justifies the use of contract-based hog production units and their coordination with animal processors. The frailty of confinement hogs results from their genetic characteristics, from the conditions in which they are raised, and from a production rationality that equates animal health with production efficiency. I detail the multiple-site methods, confinement technologies, and contract-based production organization required to raise biologically fragile hogs. And I link hog biology directly to the unequal contract-based relations between actors in industrial pork networks. My study emphasizes the relevance of ethnographic analyses within a political economy of agriculture by describing specific relations of inequalities in local and regional production units and distribution networks that form the building blocks of larger global agro-food systems.