It was a little bit like the plot of an Alfred Hitchcock movie...
We use an electric fence to keep the herd buffalo on our farm. An electric fence is a psychological barrier for these powerful animals. To the buffalo psyche, a zap from the fence processes like a wolf nip. They touch the fence; they get bit by its electricity, and they move back to the safety of the herd. This is generally safer and more effective than a barbwire fence. Brilliant on a psychological level, the electric fence is not a physical barrier at all. Absent its electric charge, the fence is a flimsy structure.
By September, our fence is usually losing a lot of its electric charge because of late summer vegetation growing up into it. Most years, we start clearing the year's growth of vegetation off of the fences about now. Normally, this is not direly urgent work; our animals have been trained to the fence. On occasions, we've even turned the fence off for a month or more at a time, and the animals didn't bother it.
This summer, a perfect storm struck. Our tractor that we would usually use to rapidly clear long stretches of fence line has been at the shop waiting on a tune up for months. Our weed whackers are also at the shop. As we waited on these repairs, the fence charge dropped down to 1,900 volts, low enough that our calves could squeeze through our 3-wire cross fences - We began on the pretty hardcore task of clearing our 6 miles of fence line using only a rake and two pairs of hand-powered clippers. Then, some of our buffalo cows went into season a little late, causing tension in the herd at the very time the fence charge was at its lowest. As a result, "Spike", our yearling bull started breaking gate handles - We began working earnestly now, spending every available daylight hour clearing fence. Soon, the herd started appearing in random pastures, going through interior gates demolished by Spike . - Now, we had a mile and a half of fence line completely cleared, but the fence charge hadn't risen at all. Within days, Spike started breaking our 1000-lb-strength main fence wires - By this point, we had our two mile perimeter fence completely cleared and another mile of cross fence either cleared or disconnected, but the fence charge still hadn't increased. The animals were now just one step away from tearing through the exterior fence, heading down the highway, probably getting themselves killed, and leaving us behind to pay for the damages inflicted on the county in their cross-country spree. With our own stress level starting to rise, we disconnected the perimeter fence from the cross fences to concentrate all of the available electric charge on the perimeter. Still the charge didn't increase! As a last resort, we put the herd in our "training pen" - a secure place protected by a strong fence with six wires. This is where we bring animals to train themselves to the electric fence. The very next morning, Spike and four calves had slipped through.
Vegetation on the fence had been a problem. Since the fence charge didn't change when all of that vegetation was removed, it meant there was also another problem, either a bad energizer or an unseen short. The latter is a little frightening because the short could be anywhere along miles of fence line, even underground and invisible. I took a day off work and managed to find a tiny end of a wire that was touching against another wire and shorting the fence out. With that short fixed, the fence was instantly running at 7,800 volts.
The charge comes in pulses only a fraction of a second in duration so that the fence doesn't kill an unfortunate animal that comes into contact with it... I once forgot our fence was on and slipped between its wires when it had about 6,000 volts on it. The result was good-sized electric burns on my chest and back. Another time, I managed to face-plant into the fence when it had 10,000 volts on it. I was knocked unconscious, but otherwise unhurt, just a singed/metallic taste in my mouth...as I said, an unfortunate animal. Bison, with their insulating wool and hooves are less vulnerable to the bite of the fence than human skin is, but at these voltages even they feel the jolt. Now that a few of our animals are bona fide fence-destroyers, we have to train them to respect the fences all over again. We do this by keeping them in the training pen for a while to get re-acclimated to a fully charged fence.
We spent weeks clearing miles of fence line with hand-clippers, taking hundreds of thorn scratches and losing gallons of sweat in a sweltering Oklahoma September. We did this to keep in animals that, even though they had an abundance of fresh grass and water, were bent on destroying these fences and getting out. Of course, had they been successful it probably would have meant their own deaths. At the end of it all, right after we had finished hand-rolling the last of eight very heavy hay bales into the training pen to feed these endearing animals, we heard a familiar noise. An animal was trying to push through the fence. In touched it's moist nose to one of the energized wires and POP!!! BEEEEH!!! It was the sound of a fence-destroyer suddenly wanted nothing more to do with that fence. The humor of the moment repaid many debts.
Epilogue. Two days after we got the fence back up and working, Spike pushed through another gate. Any animal willing to go through a nearly 8,000 volt shock to damage a fence is pretty much unheard of, but leave it to a buffalo bull. We'll keep working with him in the training pen for the coming weeks, but if he refuses to respect a fully charged fence, we'll be left with only one final option - making him an appointment at the Oklahoma Bison Association Fall Sale in November.