Several years ago, Wisconsin producer Ray Walter purchased a commercially built mineral feeder with an insecticide curtain for fly control in his beef herd. The unit, however, was difficult to move from one pasture to another and its high price discouraged him from buying more. Instead, he built his own sturdy, portable feeders with 6 x 6 and 2 x 12 lumber. He added a polyethylene tank and synthetic yarn mop, purchased from a local farm-supply store, for pesticide application. Fly control, he says, has been very good. An entry from the back of the feeder allows Mr. Walker to fill the feeder without exposing himself to the pesticide applicator. Materials for the feeder, he says, cost about $200, and the pesticide tank and mop cost another $68.50. Mr. Walker adds that he designed the feeder to be easy to move, either by pulling or by carrying with the round-bale forks on a tractor.