Iowa farmers could be the big losers in the mega-merger between Tyson Foods and I-B-P, according to Iowa Senator Chuck Grassley. A federal judge has ruled poultry giant Tyson must go ahead with its plan to buy beef and pork packer I-B-P, which Grassley says is very disappointing.Tyson had terminated its plans to buy I-B-P for three-point-two billion dollars after learning about financial problems. A judge ruled Friday the acquisition must go forward, and Grassley says it’ll hurt competition and it’ll hurt Iowans.Grassley plans to ask the Justice Department to take another look at his original letter from several months ago, opposing the proposed merger. Tyson is based in Arkansas. The former Iowa Beef Packers is now based in Dakota Dunes, South Dakota.