We live on a mountain with deer, moose, elk, bear. Quite a few years ago when we first planted our orchard, we would wake up in the morning to hear that whistling call of the deer and they would be munching away on our little trees. But we didn't get serious about this until a bear took out our bee hives.
We built a New Zealand Electric Fence around 3 1/2 acres. My husband bought long cedar rounds from a neighbor who was logging and split them for the posts, bringing the cost down. Every other wire is hot. We put the insulators on the outside. We have a solar electric system and the timed electric pulses do not use a lot of electricity. Drawback is that if your dogs detect an large animal who makes it inside, he could pull the insulators off in his escape, even if you put them on the outside. Also snowload will destroy the corners. We ended up putting really big timbers on the corners. You have to weedeat brush regularly in the summer. There is a lot of maintenance, but all in all, the fence helps enormously. Some smaller animals can time their entrances and exits and get by without being hit part of the time, but eventually when they get a good hit, they stay away. I have walked to the outhouse in summer and spooked something hiding in the brush which hightailed it out the fence. I couldn't see what it was for the high brachen fern. We have had smaller bears get in in the early spring and get the hives again. A good cheaper source of some items is Kencove Fence, www.kencove.com. Merla Barberie