Encyclopedia
Please note this is a comparison between Version 1 by Piotr Goliński and Version 2 by Lindsay Dong.
Maximizing annual pasture consumption without negatively impacting individual cow performance is of great importance in grass-based dairy and beef systems due to pasture being the most cost-effective nutrient source. However, the disadvantages of conventional and electric fencing include material and labor costs and increased manual labor. Virtual fencing has been developed and evaluated for almost two decades. The evolution of precision livestock farming, specifically virtual fencing, presents new opportunities for maximizing the utilization of available pasture land. Virtual fencing technology decreases the labor involved in physical fencing, provides greater adaptability to changes in pasture conditions, increases precision and efficiency, and offers additional flexibility in grazing management practices. However, that innovative technology should be further developed, and improvements should include decreasing the total costs of the system and increasing its application to other technological groups of ruminants, e.g., suckler cows with calves, increasing the efficiency of the system operation in large areas and a larger number of animals.
- cattle
- grazing
- herd management
- pasture
- virtual fencing technology
1. Virtual Fencing for Grazing Animals
Precision livestock farming is a concept in livestock farming using a variety of sensors and new technologies to improve the management capacity for big groups of animals [1][29]. One of those new technologies is the virtual fencing solution [2][30]. Improvements in grazing management should aim to optimize the soil-plant-animal relationship. To achieve this, a rotational grazing system that accurately allocates pasture is necessary. This will help to minimize wastage (over-allocation) or avoid negative impacts on pasture and cow performance (under-allocation) [3][4][31,32]. Virtual fencing has the potential to enhance the efficiency of grazing management. One major advantage is flexibility in managing stocking density. Virtual fencing technologies have expanded the possibilities for spatial and temporal control of animal grazing and nutrient transfer events [5][6][33,34]. It was first used to control the location of livestock in 1987 [7][35]. Virtual fencing is an enclosure, barrier, or boundary without a physical fence [8][27]. It allows real-time automation of grazing management, enabling the use of complex grazing systems to improve pasture and cattle management [9][10][36,37]. Virtual fencing is a part of digital technologies which may optimize animal productivity while minimizing environmental impacts [11][12][38,39]. Combining virtual fencing with decision support tools based on technologies for measuring environment variables, pasture availability, quality, and cattle performance provides the opportunity to create a step-change in the way cattle are managed [13][14][5,40].
The general idea behind the innovative grazing technology using virtual fencing based on an IoT system [15][16][17][41,42,43] is controlling animal behavior (stopping or changing the direction of movement) by employing stimuli (sound or very low electric current) generated by a collar-mounted device worn by the animals [6][18][34,44]. Virtual fencing works mainly by putting a collar on each animal which can administer auditory warnings (82 dB, 1 m) and low-energy electric pulses (0.2 J, 3 kV, 1.0 s). In addition, on-animal sensor devices are also being developed to assess behavioral variables such as time spent grazing or eating, ruminating, walking, lying, and drinking, and other cattle performance, health, and welfare-related parameters [19][20][21][45,46,47], including intake of pasture [22][23][48,49].
All virtual fencing technologies use more or less the same principle in which a collar with GPS is continuously tracking the position of the animal and checks this against the virtual borders set by the farmer and downloaded on the collar (Figure 1). If the animal approaches the virtual border, the collar will produce an audio signal whose intensity and tone scale increase when the animal comes closer to the border. If the animal does not respond to the audio signal, it will receive an electric pulse. The pulse has about 30 to 50 times less energy compared to a traditional electric fence, but still, it is enough for the animals to be considered unpleasant. The cycle of the audio signal followed by the electric shock is repeated one to two more times if the animal does not respond, the animal is indicated as ‘escaped’ (Figure 2), and the audio signals and electric pulses are switched off until the system is reset if the animal returns to the allowed zone. The farmer gets push messages when an animal receives an electric pulse or when it is ‘escaped’, and he can get live information on the position of each individual animal and the number of audio warnings. The collars have built-in solar panels to charge the batteries during the day.
Figure 1.
General concept of virtual fencing for grazing animals.
Figure 2. Possible response of grazing animals to virtual fencing.
2. Innovative Systems of Virtual Fencing
Analysis of global patent databases revealed several solutions based on virtual pasture fencing technology using IoT. The first ideas regarding using audible signals emitted by a collar-mounted device worn by an animal appeared around half a century ago but did not initially apply to livestock. The primary purpose of such systems was to control the behavior of companion animals (dogs and cats) with audible signals to discourage them from approaching or passing through the existing fence. Peck [24] turned the concept of virtual fencing into reality with his patent (December 1973, USA) describing a method and apparatus for controlling animals. Later in 1987, Peck’s Invisible Fence manufactured the first virtual control devices for domestic livestock in the United States [7].
2.1. eShepherd
One of the virtual fencing technologies is eShepherd
Possible response of grazing animals to virtual fencing.
2. Innovative Systems of Virtual Fencing
Analysis of global patent databases revealed several solutions based on virtual pasture fencing technology using IoT. The first ideas regarding using audible signals emitted by a collar-mounted device worn by an animal appeared around half a century ago but did not initially apply to livestock. The primary purpose of such systems was to control the behavior of companion animals (dogs and cats) with audible signals to discourage them from approaching or passing through the existing fence. Peck [56] turned the concept of virtual fencing into reality with his patent (December 1973, USA) describing a method and apparatus for controlling animals. Later in 1987, Peck’s Invisible Fence manufactured the first virtual control devices for domestic livestock in the United States [35].
2.1. eShepherd
One of the virtual fencing technologies is eShepherd
®, developed and commercialized by the Australian company Agersens (Melbourne, VIC, Australia) (acquired by the New Zealand company Gallagher). This system utilizes intellectual property that has been licensed and developed by the Commonwealth Scientific and Industrial Research Organization [18][25][26][27] and is commercialized for cattle. The cost of eShepherd technology is estimated as €60–90 for one collar and €5000 for infrastructure [28]. Virtual fencing uses the global positioning system (GPS) to assign location, movement, position, heading, and speed to cattle, and it communicates this information using neckband-mounted devices. Moreover, the GPS is used to specify the virtual fence boundary (separating inclusion vs. exclusion zones), which is transmitted to the unit using a radio frequency link. The cattle neckband consisted of a strap and hanging counterweight (total weight ~1.40 kg), and the unit (~725 g and 170 mm length × 120 mm width × 130 mm height) on the top of the animal neck and the solar-powered base station. The system controls animal behavior through a radio-controlled device. A transmitter on the neckband generates two types of stimuli—audio and electric [29][30]. An animal approaching the boundary of the virtual fence (determined by the mobile app) receives a signal to stop or change direction in the form of a sound of about 785 Hz. In addition, in the absence of the desired response to the auditory stimulus, an electric pulse with a relatively low voltage of 800 V is sent [31][32][33][34][35]. An audio cue followed by an electric pulse sequence was repeated if the animal continued through the fence line and into the exclusion zone. At this point, it should be added that in the case of conventional electric fences, the electric pulse voltage generated by the electrizer (so-called electric shepherd), among other things, is 2000 and 4000 V in summer and winter, respectively. When the animal reacts positively to the first signal (i.e., stops or turns back), the device does not generate another stimulus, i.e., an electric pulse.
2.2. Nofence
, developed and commercialized by the Australian company Agersens (Melbourne, VIC, Australia) (acquired by the New Zealand company Gallagher). This system utilizes intellectual property that has been licensed and developed by the Commonwealth Scientific and Industrial Research Organization [44,50,79,80] and is commercialized for cattle. The cost of eShepherd technology is estimated as €60–90 for one collar and €5000 for infrastructure [81]. Virtual fencing uses the global positioning system (GPS) to assign location, movement, position, heading, and speed to cattle, and it communicates this information using neckband-mounted devices. Moreover, the GPS is used to specify the virtual fence boundary (separating inclusion vs. exclusion zones), which is transmitted to the unit using a radio frequency link. The cattle neckband consisted of a strap and hanging counterweight (total weight ~1.40 kg), and the unit (~725 g and 170 mm length × 120 mm width × 130 mm height) on the top of the animal neck and the solar-powered base station. The system controls animal behavior through a radio-controlled device. A transmitter on the neckband generates two types of stimuli—audio and electric [53,82]. An animal approaching the boundary of the virtual fence (determined by the mobile app) receives a signal to stop or change direction in the form of a sound of about 785 Hz. In addition, in the absence of the desired response to the auditory stimulus, an electric pulse with a relatively low voltage of 800 V is sent [24,54,83,84,85]. An audio cue followed by an electric pulse sequence was repeated if the animal continued through the fence line and into the exclusion zone. At this point, it should be added that in the case of conventional electric fences, the electric pulse voltage generated by the electrizer (so-called electric shepherd), among other things, is 2000 and 4000 V in summer and winter, respectively. When the animal reacts positively to the first signal (i.e., stops or turns back), the device does not generate another stimulus, i.e., an electric pulse.
