I've seen deer in the same fields as cattle, but they usually aren't standing close together. A farm I hunted in college had a field of 30 or so cattle, and while I never saw any deer in that field, there was a lot of sign on the back side of the field just outside of the fence. During one bowseason I sat up a ground blind on that fence row looking into the woods, with the pasture at my back. I figured out a couple things real quick...if the cows saw me walk in and sit down, they would slowly work their way towards me and stop about 20 yards behind me and eat/stare until I left. I found a way to sneak in without them seeing me which worked well until I used my grunt call one afternoon. I don't know what it was about the grunt call, but every cow in that field was once again standing behind me within 10 minutes. Didn't take me long to find another spot to hunt. 30 cattle standing 20 yards behind you gets loud and annoying real quick.

--Man who fish in other man's well often catch crabs--