In loose form, I provide kelp, sea salt, copper sulfate, sulfur, dolomite, calcium carbonate, baking soda, monocalcium phosphate (probably won't re-buy this one now that I got the calcium carbonate), and Fertrell Goat Nutribalancer.
Zinc and Vitamin E will be will supplied in kelp. Kelp will be the best way to get minerals; it is far more effective.
I add Fertrell mineral mix to provide the trace minerals such as cobalt, manganese, phosphorus, etc. These are not necessary to add out free choice, but the goats seem to love it so there must be something in there that they need.
Did you test your soil to know the copper levels?