In a veto message issued Friday, Christie called the bill opposing gestation crates a "solution in search of a problem."
"It is a political movement masquerading as substantive policy," he said.
The crates, which are so small that pregnant pigs can't turn around in them, have been criticized by animal welfare activists as cruel. Pigs can spend years in them, and advocates say they don't want their use to spread.
The bill had overwhelming support from Republican and Democratic state lawmakers but would have had little to no impact in New Jersey, whose roughly 300 pig farms don't regularly use the crates.
But the crates are widespread in Iowa, which is home to millions of pigs; it's also home to the nation's first presidential nominating caucuses. Christie has invested significant time building relationships in Iowa, campaigning on behalf of its Republican governor,
New Jersey state Sen. Raymond Lesniak, a Democrat and the bill's lead sponsor, expressed disappointment after the veto and accused Christie of "capitulating to political influences in a state thousands of miles away."
"Obviously, the governor is putting his personal political ambitions ahead of the humane treatment of animals," he said.
The fight over the legislation had become one of the most heated in recent memory.
Animal welfare advocates launched a public relations blitz, complete with celebrity endorsements and staged events at which activists stood inside cages. They also commissioned polls to show support for the ban in New Jersey and Iowa and said they flooded the governor's office with thousands of phone calls and emails.
The National Pork Producers Council, based in Washington, D.C., sent a lobbyist to New Jersey to try to scuttle the attempt. It was pleased with Christie's action.