Salt and Minerals draw Deer in for trail camera pictures,to enhance Antler growth in Bucks and it helps Doe's in milk production for Fawns.....and if Your Hunting You may get a shot at a nice Deer?
Same reason we use Doe Pee,Doe in Estrous scent and Buck Urine on scrapes....another way to draw Deer in to Your Hunting area.
Same reason we rattle Deer Antlers to get a nice Big Buck to come for a fight or use a grunt call or Fawn bleat.....to draw Deer in when Bow or Rifle Hunting.