I raise cattle and hunt deer. The elec fence will work but deer don't like being shocked any more than cattle. I would not worry about fencing it, let the cattel & deer mix, they do very well. I have deer tracks around my stock tanks all the time. Easy place to get a drink.

Cattle might get into your feed plot but usually by deer season around here(Kansas) cattle are off pasture & in a lot being fed bales.
Jim