Pounding rainstorms have turned Southern California dairy farms into swamps so thick that cows cannot walk or sleep, and 6,500 of them have dropped dead of exhaustion.

Milk production in a dairy preserve that spreads over 10,000 acres about 40 miles east of Los Angeles has dropped 7 percent this month. The losses could be much higher as cows grow weak from rain-bred infections."It's terrible and it's getting worse," said Bob Feenstra, executive manager of the Milk Producers Council, which represents most of the 300 dairies in the area.