Cargill Right Now(R) Onyx mineral supplement provides essential year-round mineral fortification for optimizing herd performance when cattle are under stress. The trace minerals in Right Now(R) Onyx are readily absorbed into the bloodstream and help supply animals with a complex blend of organic zinc, manganese and copper. May be added to the feed mix or offered as a free choice. | Right Now Mineral Onyx Black Cattle Mineral | Size 50 lbs