According to this account, the documentary has been effectively censored in the U.S.:
… That’s how it’s gone with the British 2009 documentary film Pig Business. I watched this film in several 10-minute segments via YouTube (Part One) because it hasn’t been released in the U.S., primarily due to legal pressure brought upon the director (Tracy Worcester, who spent four years making the film) by the film’s main villain, Smithfield Foods. The world’s largest pork producer, Smithfield has 52,000 employees processing 27 million pigs per year in 15 countries, accruing annual sales around $12 billion. The UK’s Channel 4 ran the film last summer despite four letters from Smithfield threatening litigation, but since no U.S. insurer would back the film’s release here, it has become essentially a black-market film. Score another one for corporate censorship.