Do deer eat rotting apples or just fresh fallin ones?

I have seen them eat both

they eat all of them in my yard. It usually takes them until April to clean them all up, digging through snow to find the frozen ones when necessary.

Seems like you get some that prefer them more than others. They also have a preference for different varietys at different times.

I would say all of em because my yard is bare. They like pears and crab apples too.

I use to watch the does get on there back legs and fight each other over peaches in my back yard. cool stuff.

I threw some apples that were going bad out on the trail behind my house. A couple of hours later I was taking the dog for a walk and saw that they were already mostly gone.

They'll eat most any condition, fermenting apples as well. They especially love the pomace (pronounced same as "pumice"), the somewhat dried fibrous residue leftover from making cider; the local hunters flock to the orchard to get pickup loads of the stuff for bait. Not legal, but - we all know plenty of "hunters" that don't have much regard for laws. And Rico is right on the money - I've seen them at the pomace piles in the winter at the orchards, some will not touch an apple in the pile (the apples not fit for cider-making are sorted out and tossed into the pile) while others root through the pile like pigs trying to find the apples.