My $.02  on perimeter fence-  5 wire with 4 the heavy gage red brand barb and the middle wire a smooth high tensile on insulators with a 6 joule charger on it.  The hot wire keeps cows from pushing on the fence to get some green on the other side.  Every 5th post a 6" wood 4 steel tee posts in between. Middle hot wire also gives you a place to use a gate handle to tap juice for moveable cross wires.

In a deer area I would NOT electrify any wires near the top because those are the ones they catch jumping over and cause to short out etc. jmho. 

As my neighbor says the best way to keep them in is to have enough to eat on their side.

Jim