WEST MANSFIELD, Ohio  Concessions by farmers in this state to sharply restrict the close confinement of hens, hogs and veal calves are the latest sign that so-called factory farming  a staple of modern agriculture that is seen by critics as inhumane and a threat to the environment and health  is on the verge of significant change.

A recent agreement between farmers and animal rights activists here is a rare compromise in the bitter and growing debate over large-scale, intensive methods of producing eggs and meat, and may well push farmers in other states to give ground, experts say. The rising consumer preference for more “natural” and local products and concerns about pollution and antibiotic use in giant livestock operations are also driving change.

The surprise truce in Ohio follows stronger limits imposed by California voters in 2008; there, extreme caging methods will be banned altogether by 2015. In another sign of the growing clout of the animal welfare movement, a law passed in California this year will also ban imports from other states of eggs produced in crowded cages. Similar limits were approved last year in Michigan and less sweeping restrictions have been adopted in Florida, Arizona and other states.

Hoping to avoid a divisive November referendum that some farmers feared they would lose, Gov. Ted Strickland of Ohio urged farm leaders to negotiate with opponents, led by the Humane Society of the United States. After secret negotiations, the sides agreed to bar new construction of egg farms that pack birds in cages, and to phase out the tight caging of pregnant sows within 15 years and of veal calves by 2017.