California hay growers have had an increased market for their dairy-quality hay -- 49,000 milk cows were added to the state's cumulative herd from September of last year to September 2007, according to a USDA report. At least 8.4 million milk cows were reported within the 23 major milk-producing states as of last month. That's an increase of 91,000 cows over the September 2006 number, and 12,000 more than reported in August 2007. Minnesota added 13,000 cows; Wisconsin, 4,000.