That's what I do. My current house came with a small neglected orchard with trees 10-15 feet tall. It was pretty easy to see the height the deer reach in their browsing so I've just raised the canopy up to that height.

On the plus side, having the canopy higher makes it easier to maneuver under the trees for things like mowing.

My newer trees I have either surrounded with deer net individually or in groups with the idea that I will remove it when the trees are tall enough to thrive without any leaves below 6 feet or so.

Some trees I wasn't sure about I left unprotected. I learned the local deer will eat persimmon and hardy kiwi leaves. They mostly leave feijoa (pineapple guava) and pawpaw alone and they haven't seemed to touch the figs, mulberry or olive at all.

Contrary to what I'd heard, they also eat black currant seemingly in preference to red and white (or maybe its just the location).

I know they really like apple, quince, aronia and plum.

About 6 years ago, I helped prune some trellised apple trees on an island in the Puget Sound for a church farm....I was not happy to see the deer were eating all the apples and the leaves as well at 5 or 6 feet or lower on all of these fine apple trees.....
but I WAS indeed happy to see in the Autumn that this orchard did not have an apple maggot problem and I had to wonder if the deer were actually just doing a perfectly good job of "sanitizing" the orchard every night and eating up all the apples on the ground before the apple maggot larvaes had a chance to exit the apples after the apples had fallen that day.
Deer me ! Good or bad is sometimes a matter of perspective.

Donnie,
I've wondered the same thing - about the critters 'sanitizing' - or at least diminishing the number of larvae of whatever insect pests that get a chance to mature and infest the fruit next go 'round.
Ever since the deer 'discovered' my orchard in 2007(knew I should have 'offed' those two orphan fawns that spent the summer there after their dam died of EHD), there are not many 'windfalls' that persist for any length of time, and at some times of year, I find many apples pulled from the trees, or still hanging on, with deer toothmarks on them.

I have a dozen weaned & yearling heifers up in the pasture by the barn this year, and have been picking up all the damaged/windfall/June-drop apples in the orchard, quartering them, and feeding to the heifers every evening.

Good point about the insect control. I've noticed that there are no codling moth or apple maggots in the few apples that these trees produced.

I assumed it was because there aren't any other apples within hundreds of feet, but had considered that the deer may be helping.

If you cut to many lower branches, you can basically make the tree a giant wind catch, and make it a bit more suceptible to wind damage.

You can try to plant a "Deer deflecting" hedge, consiting of spikey plants the deer wont go though, and plants the deer CAN eat, to try and distract them from the good stuff. Try Caregana, trifoliate orange, native roses and even other fruits like manchurian apricot or wild plum. The latter you can graft more desierable species on to the non deer side.

http://www.scribd.com/doc/60996039/Toby-Hemenway-Gaias-Garden-Second-Edition-A-Guide-To-Homescale-Permaculture-pdf

Scroll down to page 11 "gardens that REALLY work with nature"