Smithfield’s pigs live by the hundreds or thousands in warehouse-like barns, in rows of wall-to-wall pens. Sows are artificially inseminated and fed and delivered of their piglets in cages so small they cannot turn around. Forty fully grown 250-pound male hogs often occupy a pen the size of a tiny apartment. They trample each other to death. There is no sunlight, straw, fresh air or earth. The floors are slatted to allow excrement to fall into a catchment pit under the pens, but many things besides excrement can wind up in the pits: afterbirths, piglets accidentally crushed by their mothers, old batteries, broken bottles of insecticide, antibiotic syringes, stillborn pigs — anything small enough to fit through the foot-wide pipes that drain the pits. The pipes remain closed until enough sewage accumulates in the pits to create good expulsion pressure; then the pipes are opened and everything bursts out into a large holding pond.