Lonny,
The only difference we can taste is SOMETIMES mature mule deer bucks get a little off-flavor during the latter part of the rut. This mostly settles into the connective tissue, so large cuts like hams, steaks and backstraps don't develop it much, if at all. It also seems to increase after several months in the freezer. Have noticed it after about November 15th here in Montana.
We have yet to taste any hint of that in the meat of mature rutting whitetail bucks, and we've taken them all through November not only in Montana but several other states.
As several other people noted, if whitetails and mule deer are eating the same stuff, the meat tastes very similar. Which makes sense, as they're so closely related they can interbreed--and often do.
