in my opinion people feed way too much mineral. most minerals should come from your forage. if you have a variety of grasses & legumes , they should not lack much. they mix salt with the minerals so cows will eat more mineral than they need. you can get your hay tested to see if you lack any minerals. never fed much mineral til i came out here & had all fescue to start with. now i have better grass with legumes & feed mostly salt with a little mineral mixed in now & again or use trace minerals now & again. you can look up minerals needed for missouri on the net also. mineral co. want you to use more to line their pockets. they used to claim if you put minerals out separately cows would pick out what they needed. but have disproved this