I had this, mainly with treats, not so much with hard feed. My boy didn't stop at licking the door, he started to bite it. I was worried it would lead to cribbing so now when I give treats I generally give them outside the stable.
My horse does this, well he licks the metal bars & wall top between his stable & his neighbour's; has done ever since living there. The metal is all shiny where he has licked! But has never developed into biting or cribbing or anything, he just likes a good old lick after hard feed or treat. Does it even when he has a stable lick too. So prob nothing to worry about.
Its weird isnt it, there was a horse that used to do it at the riding school when i was a kid. He used to lick all up the supports for the door every time he had a feed
three out of the four geldings on our yard do it. Maybe its a gelding thing??
My boy licks my back when Im picking his feet out and loves to lick my hubbys head
My boy does this too after his mint, which he has after a ride. He has to lick something and will lick you if you don't get out of the way quick enough!
my girl does this generally lol doesn't have to be after a feed mind you she licks everything: me, my hair, the little pony(not immpressed) wheelbarrow,stable door, bench you name it she will lick it lol