As reported by the Wall Street Journal's Washington bureau blog:
Proposition 204, known as the Humane Treatment of Farm Animals Act, passed with 62% of the vote Tuesday, mandating that pig producers house sows in pens larger than the two-by-seven foot “gestation crates” currently used. Arizonans for Humane Farms, the key interest group supporting the measure, called the crates inhumane because they prevent the pigs from turning around or stretching their legs. Major funding for the campaign came from national animal welfare organizations, including the Humane Society of the United States and Farm Sanctuary.
The Campaign for Arizona Farmers & Ranchers, a coalition of state pig producers against the proposition, became known for its blaring yellow and black HOGWASH signs along state highways.