Subject is exactly poultry processing
As part of an extensive Wall Street Journal report on dead-end jobs, Tony Horwitz posed as a worker in two poultry processing plants, in many ways the epitome of the "often-unseen harshness of low-wage work." The other two pieces in the Journal series, both available on the Pulitzer Prize site, do not involve undercover poses. Horwitz, however, has used the technique in previous efforts, both to investigate what was happening in the massage parlors of Fort Wayne, as a cub reporter in Indiana, here included, and to get around military restrictions during the Gulf War. He also has dressed to fit in while cultivating sources as he reported on Confederate re-enactment for his later books).
Reporters have taken the undercover route from slaughterhouses and chicken- and pork-processing plants to fast-food chains and supermarkets to understand the system.