Two groups that are usually squawking at each other — egg farmers and animal welfare advocates — announced an unusual agreement on Thursday to work together to seek a federal law that would require larger cages and other improved conditions for the nation’s 280 million laying hens.
The deal comes after the egg industry has been put increasingly on the defensive. Animal welfare groups have clandestinely recorded videos showing poor conditions on farms, and various states have sought to set more humane standards for hens. Egg producers have also been struggling to improve their image after tainted eggs from several farms in Iowa sickened thousands of people in a nationwide salmonella outbreak last year.
The agreement was announced by the nation’s main egg industry group, the United Egg Producers, which represents farmers who own about 80 percent of the nation’s laying hens, and the Humane Society of the United States, the nation’s largest animal protection organization.
The groups said they would ask Congress to pass a law enacting the new standards, which they said would be the first federal law addressing the treatment of farm animals and would pre-empt efforts in several states to set their own standards.
The proposed federal standards would include cages that give hens up to 144 square inches of space each, compared with the 67 square inches that most hens have today. They would also include so-called habitat enrichments, like perches, scratching areas and nesting areas, that allow the birds to express natural behavior.
“We always feel that if we can work with the folks who are handling the animals and get them to agree to improve standards, that’s the best outcome,” said Wayne Pacelle, chief executive of the Humane Society. “We don’t have to be locked in combat forever. That’s not our goal. Our goal is the welfare of animals.”
The industry said the changes, in most cases, would be phased in over the next 18 years at a cost of $4 billion.
It is far from clear whether such a law could be passed. One potential obstacle is opposition from other poultry or livestock farmers, who may be worried that similar laws could some day apply to them.
In a statement Thursday, the National Pork Producers Council said that a federal law regulating living conditions for hens “would set a dangerous precedent for allowing the federal government to dictate how livestock and poultry producers raise and care for their animals.”
Robert L. Krouse, chairman of United Egg Producers, acknowledged the difficulties ahead.
“That’s part of what we have to do, as United Egg Producers, is talk with these other groups and hopefully get them to see our point of view,” said Mr. Krouse, an Indiana egg farmer. “We understand their concerns, but this is about egg producers, this is a solution that we’ve found for us.”
Mr. Krouse said that the group would also have to persuade its members to support the plan, since the negotiations were kept secret until Thursday’s announcement.
The egg producers said they wanted a federal law that would take the place of laws and regulations popping up piecemeal in several states, often with varying or inconsistent standards. One of the most significant state laws is a ballot measure passed in California in 2008, which says that laying hens, veal calves and pregnant sows must have enough room to stand up, turn around, lie down and fully extend their limbs.
For its part, the Humane Society agreed to give up on a push to ban cages entirely in exchange for the opportunity to work toward a single, nationwide standard mandating better conditions. The group also said it would shelve efforts to get initiatives onto the ballot in Washington and Oregon, and would agree not to conduct undercover investigations at large egg farms unless it was aware of especially egregious practices.
The groups said they had not yet sought to round up support in Congress for their proposal.
A federal law would be intended to pre-empt state laws. But the groups said it would have to include a faster transition timetable for California egg farmers to match the schedule approved in the ballot measure there, which requires larger cages by 2015.
Mr. Pacelle said that the activists’ strategy of seeking to enact changes through ballot initiatives had limits because some of the biggest egg-producing states, including Iowa and Indiana, did not have a mechanism to submit proposed laws directly to voters.
Aaron S. Gross, the founder of Farm Forward, a farm animal welfare group that was not involved in the agreement, said it represented a landmark shift in thinking for a segment of the farming industry.
“The industry moving from saying anything goes to saying there should be legal limits at the federal level is an enormous difference,” Mr. Gross said.