SACRAMENTO (AP) - Air regulators said Monday that dairies are the number one source of smog-producing pollution in the San Joaquin Valley, producing more than even cars and light trucks. In a much-disputed report released Monday, the San Joaquin Valley Unified Air Pollution Control District determined that a cow annually emits 19.3 pounds of volatile organic compounds, the gases that contribute to smog. That's 50 percent more than currently thought. At that new rate, dairies in the San Joaquin Valley produce more than 50 tons of VOCs a day, exceeding the amount released by cars and light trucks in the...