Think ahead and prevent flies from raiding your cattle. McGregor General Store offers Purina’s Wind & Rain Fly Control Mineral Tubs to decrease the fly population around your cattle. We have them in 125lb. and 225lb. tubs. Purina’s Wind and Rain® Fly Control minerals are designed to reduce fly populations. Flies cause significant discomfort for cattle. As part of an integrated fly control program, Purina’s Wind and Rain with Altosid (MTH), helps restore cattle comfort while reducing factors that cause poor performance, and decreased grazing time.