Could your ranch go fenceless?

Don’t laugh: This is a real product. A virtual fence technology for cattle works like the invisible fence for dogs. Each cow wears a neck collar that delivers a warning beep if the cow approaches the invisible boundary, then a small shock if it crosses it. Over time, they learn to heed the beep to avoid the shock.

Unlike a dog fence, which relies on a buried cable to set the boundary, the boundaries for cattle are broadcast by a radio signal from a base station. The cows’ location relative to the invisible fence is tracked by a GPS chip in the collar.

The technology, from Vence (vence.io), now part of Merck Animal Health, allows users to change the boundaries for the invisible fence, from a computer or smartphone, as often as desired. Vence highlights the technology’s value in a rotational grazing system to manage cattle and grass inventory while reducing costs for labor and fence material.

One early adopter of the system is Jorgensen Land & Cattle Partnership in central South Dakota. Nick Jorgensen says the Angus seed stock operation began looking at virtual fencing several years ago and decided to buy its first Vence units in 2020, when 300 replacement heifers received collars. It’s been a steep learning curve, Jorgensen says, but it’s been mostly positive. In 2023, the ranch had collars on about 500 cows, or about half the herd. We asked Jorgensen for his assessment so far.

SF: How does the Vence system work for you?

NJ: We have four of the base stations that are connected to the internet and broadcast the boundaries on two grazing locations, one about 2,000 acres, and the other, 3,000 acres. Vence says the base station can reach out and broadcast the boundaries a distance of about three to five miles. But it really all depends on the terrain. With hills or mountains, it’s a shorter distance, and it might require multiple base stations. We’re pretty flat around here, and I’ve seen the signal travel six miles. In our case, one base unit could probably reach about 3,000 acres.

SF: Does it help you graze more efficiently?

NJ: Yes; we use it to rotationally graze cattle. Last summer, we used the system to move cattle into new grazing paddocks every three to four days, using just the collars and virtual fence. The collars are GPS-enabled, to track where every cow is at any time. When a cow gets close to a boundary we’ve set, she gets the audio signal on her collar. It’s like a loud beep. If she gets even closer, it gives her a small shock. It’s only about one-tenth the shock of an electric fence, but that’s all it takes. You’ll see them twitch their neck and back up. Most cows learn within a few days that when they hear the beep, it’s time to turn back.

SF: Do you have to train cows?

NJ: When we put the Vence collars on a group of cows, we have a conditioning period of three or four days in a 40-acre pasture that

has a real fence. We set the virtual boundary just inside the real fence. They understand the real fence, and they learn how the virtual fence works in that conditioning period. If they get too close, they hear one beep. They learn that if they keep going that way, they’re going to get a shock.

I’ve spent hours over the course of this project watching cow behavior, and one thing I’ve learned is how smart they are. You can go out there and hear all of their beepers going because they are inside the zone. They’ll graze right up to the invisible line and stop. It’s amazing how they figure it out.

SF: How hard is it to move cows from one paddock to another, with just the invisible fence?

NJ: We’ve built the paddocks around water sources that make it easier for the cows to move. When we move, we set the new boundaries, so that when cows come to drink, they’re captured inside the new paddock. They essentially move on their own, without a lot of hassle. Over the course of a day, every cow is going to come to water.

SF: Do you put the collars on cows and their calves too?

NJ: No, not on the calves. For the most part, calves stay with their mothers and don’t cross the invisible boundaries. If a calf does wander off to graze outside of the virtual boundary, it’s not really a bad thing, as that calf is grazing on the freshest grass that hasn’t been touched or trampled.

SF: Does it work? And do the cows stay where you want them without real fences?

NJ: Our farm is still on the bleeding edge of this technology, and we’re still learning where it works best and its limitations. The newest collar design from Vence is made of chain and is less likely to fail than earlier versions. The neck unit that delivers the beep and light shock is run by a battery, which is usually good for six to nine months. Batteries do run down, and power outages can disrupt the system. All in all, our experience would say the virtual fence is about 95% effective at containing animals. But any rancher can tell you that a physical fence isn’t 100% either.

This probably won’t ever replace all physical fences, at least on our farm. Like most of the Midwest, our farm is largely laid out in one-mile-square sections. I expect us to always have a real physical fence around the perimeter of those sections, so cows can’t get on the roads. But the internal fences that move the cows around to smaller paddocks for rotational grazing could be the invisible kind.

SF: What about the economics of this new technology?

NJ: That’s a tough question to answer. I know the cost to build a physical fence is about $15,000 a mile. To go all the way around a section of land is four miles, or $60,000. On our farm, if we put the virtual fence on all 1,000 of our cows, our outlay would be close to $50,000. When you look at that comparison, the virtual fence doesn’t look so prohibitive.

The question is, can you make that kind of investment and get the value back? We’re still determining that, and I don’t think we know the answer yet.

For instance, what is the full economic value of using this system to do a better job of grazing, particularly rotational grazing? Can we get enough improved productivity to pay for the technology?

SF: Do you have other thoughts on invisible fence? 

NJ: If you want to practice rotational grazing to manage cattle, grass, and water inventory, and you don’t want to invest in a lot of infrastructure, this can do that. I could see this as a way to graze cornstalk fields that no longer have fences. Think how it might work for ranches that are on leased land, where you can’t build real fences for various reasons. This would let you practice controlled rotational grazing, and help you keep track of the animals, without fences.