Missouri senators are advancing legislation to block local officials from regulating industrial farms more strictly than the state does.
Senators gave initial approval to the bill Tuesday.
The measure sparked an overnight debate over the environmental impact of large farms, local control and actions by some county officials that critics say threaten to regulate industrial farms out of existence.
Supporters of the bill say it will help ensure farmers can make a living in rural Missouri.
Industrial farms known as concentrated animal feeding operations allow for more efficient production of beef, pork, poultry, dairy and eggs. They've also stoked concerns about air and water pollution.
The measure needs another Senate vote to move to the House for consideration. Lawmakers face a May 17 deadline to pass legislation.