The group said Friday a proposed county dairy ordinance needs tougher air quality regulations.
The commission cited recommendations for enclosing dairy barns and cattle waste in a report it requested from the California Institute for Rural Studies, based at the University of California, Davis.
The recommendations proposed by the institute would add about three cents to the cost of a gallon of milk.
This topic has been gaining interest lately from corporations looking for carbon credits. American Electric Power, the biggest coal burner in the U.S., is paying Environmental Credit Corp. to put plastic tarps over lagoons holding livestock waste on farms to block methane from reaching the atmosphere.