Gosh I don't know how to answer this. Although most good grain mixes have a mineral mix in them, it is not enough to really do much about copper. What you could do is make sure that molassas isn't a huge part of the grain mix. You also can only do soo much with your minerals in certain parts of the country, making sure your minerals are not red, since red usually signals lots of iron oxide in it, but also that it contains chelated and protinated minerals. Not just copper sulfate, but copper protinates and oxides. Vicki