I have seen notable improvement in herd health at my farm after using trace mineral licks for the last 10 years. The total number of deer has not increased but now I see much fuller appearance. First big old mature buck I took on the farm was less than 120" with heavy bases and small tines. He appeared muscular with heavy bone structure and was likely well past peak and in regression. Since then, the rack sizes have improved slightly with 2-1/2 year old looking more like 3-1/2 year bucks with a substantial increase body weight.
The last few years I have started using Big Tine Mineral and Vitamin supplement for deer licks.