MANTORVILLE, Minn. (AP) - Thousands of dairy farmers in Minnesota and Wisconsin have an expensive problem. They've lost nearly 2 million acres of alfalfa to the long, icy winter. The protein-rich alfalfa is an important food source for their cows, and it normally emerges after winter. But last year's drought weakened the plants and the hard winter killed many of them, Minnesota Public Radio reported Tuesday (http://bit.ly/Zt8Nev ). Farmers normally can harvest three or four cuttings of alfalfa in a normal summer. But this year, farmers who have to replant will be lucky if they get one or two - so they're facing a short-term shortage and potential long-term problem should they be unable to replant. Minnesota lost about 750,000 acres of alfalfa while Wisconsin lost nearly 1 million acres. So far, only about 25 percent of the alfalfa lost in the Upper Midwest has been re-planted. "It's put us into a very dire state," said Lisa Behnken, a regional extension educator at the University of Minnesota Extension. "Forage production, forage needs, forage inventory are all at great risk right now." The alfalfa loss has affected numerous operations, including the Durst Brothers Farm in Mantorville in southeastern Minnesota, which Ron Durst runs with his two brothers. They milk about 1,500 cows and grow about 3,100 acres of corn, soybeans and alfalfa. Most of that crop goes to feed the cows. Durst lost all 900 acres of alfalfa. He said federal crop insurance will cover some, but not all of those losses. "I would say, with the loss of our alfalfa, and you couple with the late planting of our corn crop, I would say it's a half a million dollars here. At this point and getting bigger each day," he said with a nervous laugh. "It's a lot of money." Farmers who need to replant have been delayed by the nearly nonstop rain, especially in southeastern Minnesota. Durst has been able to re-plant about two-thirds of their alfalfa fields. He's relying on excess inventory from last year to feed his cows. "By probably late July, August, that will be gone," he said. "We've actually bought a little hay now to stretch out our own supplies. It's coming out of Colorado. It's very expensive feed - $380 a ton for alfalfa. Traditionally, it'll be $200 or less, so it's more than doubled. And that's even hard to find." University of Wisconsin agronomist Dan Undersander said the damage is the worst he's seen since 1992, and he anticipates it will force some farmers to leave the dairy business altogether. "We're hoping that we can keep a lot of these farmers in business, and that we can weather this bad economic situation with them," he said. "But certainly we will lose some number of farmers on account of this and the cattle herds will decline to some extent." Undersander said the big question will be how wet the fields remain in the next few weeks. "The best that we can hope for is that we have warmer temperatures and good moisture the rest of the season to let us recover," he said. "Otherwise things are going to get really difficult by fall." Farmers may have to wait for that warm, drier weather. Forecasters predict showers for much of the coming week across large parts of Minnesota and Wisconsin.