The Agriculture Department will buy up to $170 million of pork, lamb, chicken and catfish to help drought-stricken farmers and ranchers. USDA Secretary Tom Vilsack says the purchase for food banks and other federal food nutrition programs will help producers struggling with the high cost of feed. The announcement comes as President Barack Obama campaigns in Iowa, where he criticized Republican vice presidential candidate Paul Ryan for blocking a farm bill that could help farmers cope with the drought. Obama has pledged a wide-ranging response to the worst drought in a quarter-century. His administration is giving farmers and ranchers access to low-interest emergency loans, opening more federal land for grazing and distributing $30 million to get water to livestock.