In cattle production, mineral supplementation is the key to even weight gain and healthier animals in all growing stages. Southern States Traditions Fly Stop Hi-Mag Beef Mineral w/Altosid is the ideal mineral supplement for your grazing livestock during early spring. In the spring, foraging beef cattle may not be getting the magnesium they need. Solve the problem with Southern States Traditions Fly Stop Hi-Mag Beef Mineral w/Altosid, which also controls the horn fly population.