I have an interesting story about that.
I have a 20 acre place where there are no apples anywhere around. One year I put out some corn to do a trail cam survey and had every deer around immediately coming. I had an overabundance of apples at my other place, so I picked up a couple of five gallon buckets and dumped with the corn. I never had another deer on cam at that spot in the next few weeks - it scareed them to death!!!
However, to better answer your question - I don't think it took long for the deer where I planted the trees to immediately start liking the apples and pears. As they gradually began to produce, the deer took right to them.
You've heard me say it before, but my problem with apples is getting them to drop at the right time - my location is much different than up North where lots of apples fall during October and November. Here, most apples won't even go into October, and most crabapples just keep hanging on all winter and turn into dried up mummies. That's why I'm excited about this Kenner Seedling - it could be my best deer apple because it is going to make it to our gun season in November.
The action around this tree has been insane. Every buck on my place comes to check for apples, and many times it will still be in shooting light.