For horses, the electric fence is a psychological barrier. You understand the shock doesn't do real tissue damage, but they don't. [1] If they value freedom and learn that you can crash through the fence and feel just a moment of pain they will crash through the fence.
[1] I did find out though, that the fence really hurt a lot more when I was standing in a puddle with cracked rubber boots. I imagine it hurts more if you're heavy, well grounded, and standing on four big hooves with metal shoes.
For bears, the advice we got from Fish and Wildlife was to bait the fence with aluminum foil smeared with bacon grease. That gets the bear to touch it with their sensitive nose. If they brush up against it with their thick fur, they won't notice. A good zap on the nose will teach them.
I can confirm your note about footwear mattering. I'm way too cheap (read: stupid) to buy an electric fence tester, so I just touch the fence. In dry shoes, it's noticeable. The one time I did it in wet sneakers, it definitely got my attention. For what it's worth, we have about the smallest fencer Tractor Supply sells (it just has to go around the chicken coop). I betcha a 50 mile fencer would just about make your hair stand up on end.
My electric fence supposedly covers hundreds of miles and feels like being hit with a baseball bat. It has brought people to tears on multiple occasions. Having gotten hit a few times, I genuinely am surprised that it does not leave a visible scorch mark.
I feel bad for animals that haven’t learned about it, but anything less has proven to be insufficient for certain animals.
It does. That's a standard "party trick". You make people see how little the fence hurts and then you make everyone hold hands and the last person touches the fence and it hurts the people closer to the fence way worse
[1] I did find out though, that the fence really hurt a lot more when I was standing in a puddle with cracked rubber boots. I imagine it hurts more if you're heavy, well grounded, and standing on four big hooves with metal shoes.