The below mix is very beneficial to the deer. You can use a product called ADE minerals, in place of the trace minerals. It has all the same trace minerals but also has Vitamin A, D, & E. The vitamins help the deer's body absorb the minerals.
Calcium & Phosphorus are needed for antler growth and milk production in a 2:1 ratio. The Di-Calcium Phosphate in the mix gives you this exact ratio.
I make my own 4 part mixture, stolen from another outdoors forum and have used it for the last 11 years with good results. The salt has some nutritional value, but it is also an attractant.
1 part Di-calcium phosphate, this is a dairy feed additive bought at feed stores.
Comes in 50lb Bags, you need one bag.
2 parts Trace mineral salt, the red and loose kind without the medications. ADE minerals
Comes in 50lb Bags, you need two bags.
1 part Stock salt, ice cream salt.
Comes in 50lb Bags
I have 2 licks on my property. I put 50 lbs out in each lick in the spring and 50 lbs in each lick in the early fall. Great spot for a trail camera