Technical Note: Where are my cattle at? – Part II: Virtual Fencing
In recent years, a modern technology, “virtual fencing,” has emerged into the market and has been gaining growing interest from the livestock producers, particularly in the cattle sector. Virtual fencing technology has been studied in some European countries and Australia where grazing beef and dairy cows are predominant. More research is currently being conducted in the USA to better understand how virtual fencing might fit within cow-calf and yearling operations as a tool for grazing management. Virtual fencing can bring new opportunities for commercial success, improved pasture management, resource allocation, and economic benefits in the cow-calf industry, but the benefits of this technology require further evaluation. Research at the UNL Gudmundsen Sandhills Laboratory (GSL) ranch will begin research using virtual fencing technology to explore the efficacy of the innovative technology when compared to traditional fences.
Virtual Fencing and the history behind it
Virtual fencing refers to using technology to create an invisible area that functions similarly to the physical fence, where the cattle are managed to stay within or away from the designated areas. The first virtual fence technology was developed for research in the late 1980s, but more robust testing of different designs was conducted in the early 2000s in southern New Mexico. These early designs of virtual fence collars were large and cumbersome but provided a foundation for the technology to move from research settings to commercial-scale opportunities. With advances in computing technology and battery life, virtual fences can now work in a relatively small device that a cow wears in a collar placed on the neck.
How does it work?
If you have read our June BeefWatch article Where are my cattle at? Part I: GPS sensors, you are halfway there to understanding the science behind the virtual fencing technology! Or, if you have ever come across invisible fence collars (sometimes they are referred to as the wireless collars) for companion dogs, it is basically the same idea. Virtual fence often uses technology associated with the Internet of things (IoT) and long-range and wide-area (LoRaWAN) technologies that are explained in the previous article Part I: GPS sensors. For operations that need to cover a substantially large area or have connection (via cellular or ethernet) dead spots, multiple receivers/towers may be needed to extend the signal strengths. Wearable collars (as shown in the cover photo) include a GPS unit to locate the position of the animals and two additional units that generate an alarming sound and a gentle electric shock, all within the same collar housing if the animal is moving out of the “fencing area” based on the GPS locations. Virtual fencing area can be developed based on where the user wants the cattle to graze. Two layers of alarming systems will be initiated if the cows are moving outside the bounded area, demonstrated by the orange and red boxes – a beeping sound will be set off if the cows go beyond the orange line, and a gentle electric shock will be generated if the cows keep moving outside of the red box (Figure 1). Virtual fencing area(s) are programmed in the online software program by providing bounding coordinates (longitudinal and latitudinal). If no virtual fence information is provided or needed during this time, the collars function as basic GPS units for position locating, as indicated by the white box.
Frequent questions on virtual fencing
We received a few inquiries from producers about virtual fencing, and we have picked a few frequently asked questions.
1. What does it cost to have a virtual fence package?
The short answer to this question is, well, it depends. Currently, only a couple of companies provide virtual fencing instrumentation, and the sales mode and unit/package prices may vary. Usually, the virtual fencing is sold as a package, which includes the collar units, base tower unit, signal booster(s)/extender(s), software kit (could be a one-time fee, or more commonly, a monthly subscription fee), and installation. A maintenance fee is also possible, based on the producers’ specific needs. In addition to these base costs, a fee to cover the connectivity (either via major cellular or local internet providers) is likely needed.
2. What is the accuracy of virtual fencing collars?
Two components of the virtual fencing would encounter “accuracy” questions: 1) the effect of the collars on locating cattle accurately, and 2) the effect of the collars on managing cattle as needed. The effect of the virtual fence collars on locating cattle depends on the type, sensitivity, and accuracy of the GPS sensor used in the collars. The battery life of the collars can impact the efficiency and duration of virtual fencing. In general, if you need to monitor the herd every 30-60 mins, commercially available lithium batteries could support the collars for at least one to two months. As a rule of thumb, a greater GPS locating/sound alarming/electric shocking frequency leads to less battery longevity. More information on these topics can be found in our June BeefWatch article Part I: GPS sensors. For the effectiveness of using the technology to manage cattle, a recent study in Oregon determined that cattle stayed within the virtual fenced area 96% of the time during the first day and only were outside infrequently in days after. While not as effective as physical fence boundaries, the virtual fence was effective at manipulating where cattle grazed and significantly reduced grazing pressure in a recently burned area of pastures in their study. More research information, such as the average range of fencing variation, the size and length of the fencing zone in which the cattle receive a warning but are not outside, and the potential of using virtual fencing on strip grazing, are to be explored.
3. Does the virtual fence provide any liability for road accidents?
While virtual fences provide opportunities to manage cattle grazing, there are still limitations to their use and cattle may still go past the virtual fence or the collar may run out of battery or malfunction. In fact, to our knowledge, there is no technology or commercial product that would take the place of a physical fence. Until more research is conducted, having a physical fence line by the main roads is still needed to ensure cattle remain enclosed.
Interviews with the authors of BeefWatch newsletter articles become available throughout the month of publication and are accessible at https://go.unl.edu/podcast.