1. System overview

Animal welfare is central to Halter

In 2016, Halter was founded on our vision to unlock the connection between humans and animals. Animal welfare is central to our founding, our values and our system. It’s central to the decisions we make which advance our system.

The AgResearch Animal Ethics Committee in New Zealand approved research projects associated with the development of the product. For Halter, this was an important step in our early research and development journey that allowed us to undertake critical research that was safe and in adherence with New Zealand’s official animal welfare guidelines.

Today, Halter is the world’s only system that combines virtual fencing and animal guidance technologies. Approximately 300,000 animals and hundreds of farms are now using Halter (as at February 2025), and this number continues climbing as new farms are launched weekly. Our product development is informed by scientific literature and research on animal welfare, by Halter’s Animal Welfare Charter (section 3), by our years of experience observing and training animals, by our deep dataset on cow behaviour and by working closely with veterinarians and animal behaviour experts.

Virtual fencing and animal guidance

Cows wear a collar, and are trained to follow the collar’s guidance cues. Using the Halter app on their phone, farmers remotely shift their cows around the farm and set up virtual fences for grazing in paddocks. This reduces the need for physical fences, and motorbikes and dogs to move cows. 

The collar guides a cow using two primary cues: sound and vibration.

  • Sound cues give animals left and right guidance if they cross a virtual boundary, or turn them towards a new break, or exit point;
  • Vibration cues encourage animals to walk in the correct direction.

The collar also uses a secondary cue - a low-energy electric pulse - that is used to reinforce the two primary cues if they are ignored. The pulse is mainly used during the training period (see section 7) as animals learn to associate the consistent development of the primary cues with escalation to a secondary cue (pulse) unless they change their direction. Once animals are trained, for the typical cow the pulse is rarely used (see sections 5 and 7 for more information). A trained animal can choose to change their direction or can ignore the primary cues knowing the consequences of doing so (the pulse). The energy of this pulse is set to the lowest level that will dissuade a cow from ignoring the sound cues, if it is set any lower, they will ignore it. The pulse is significantly weaker in energy than the shock from a standard electric fence. The maximum strength of a single pulse is 0.18 joules, delivered in 20 microseconds, which is significantly less energy than the shock received from a typical mains-powered electric fence (powered by energizer units ranging from 18 to 40 joules).

If a cow moves beyond a virtual boundary, sound cues (an increasing frequency of beeps) are used to encourage the cow to move back within the break. Cows receive ample time to correct their direction and as long as they make progress to return to the break, they won’t receive a pulse. The precise time frame depends on the individual cow and their behaviour at the time, and is informed by our research into millions of days of cow behaviour to ensure cows have ample time to respond. The moment a cow moves her head in the correct direction, even only slightly, the system detects this instantly and the sound cues ease (beeping interval reduces); if she starts to walk back towards the break, the cues stop. Only if the cow chooses to ignore the primary cues and they have reached their maximum threshold, will a pulse be applied.

The pulse is used to reinforce the primary cues of sound and vibration. Because the pulse is predictable and controllable for cows, no trained cow receives a pulse she wasn't expecting. A cow will never receive a pulse without first receiving, and ignoring, the primary sound or vibration cue. The roles of the two sensory cues do not overlap, meaning different cues are never given at the same time.

Halter’s guidance system allows cows to express their normal behaviour. Once trained, the guidance cues that a typical cow receives each day are almost entirely sound and vibration. Cows are intelligent, so they learn and adapt quickly to the Halter system. Once they associate the sound cue with crossing a virtual boundary, they quickly learn to correct their direction and avoid a pulse. The typical cow receives primary cues (sound and vibration) for only 0.1% of the day (1.6 minutes per day2), meaning that for over 99% of the day they receive no cues.

(i) Sound cue

The sound cue is a benign primary cue that gives animals directional guidance if they begin crossing a virtual boundary, and is also used to turn them towards a new break or exit point. The volume is set low enough to not cause any distress. The sound cue is an increasing frequency of beeps, similar to a car’s reversing sensor.

Most dairy cows have already learnt to avoid electric fences. With electric fences, the primary cue is the visualcue; when they see a fence, they learn to avoid it to not trigger the secondary cue of an electric shock. Halter substitutes this primary visual cue with a sound cue. Instead of seeing a physical fence, cows with Halter hear where a virtual fence is. The sound cues complement a cow’s senses; cows have better hearing than humans, over a wider range of frequencies and volumes. Visually cows cannot judge distance and depth well as they only have a relatively small area of binocular vision and a binocular blind spot directly in front of them (Mounaix et al., 2014).

(ii) Vibration cue

The vibration cue is a primary cue, with a similar sensation to a mobile phone vibrating, and serves these roles:

  • When guided by the sound cues, cows receive a vibration cue if they are heading in the correct direction but have stopped moving
  • Encourage consistent cow movement to the dairy shed. If a cow stops walking forward during a shift to the dairy shed, vibration cues occur. If a cow recommences walking, the vibration will cease. If she stays stationary, the intensity of the vibration gradually increases over a 30 second period, and if the cow chooses to ignore these cues (that she is trained to understand and respond to), the pulse is applied.

(iii) Electric pulse

The low-energy electric pulse is an aversive cue that cows experience as a shock if they choose to ignore the primary sound and vibration cues. For Halter’s current version of the collar, the maximum strength of a single pulse is 0.18 joules, typically delivered in 20 microseconds, which is significantly less energy than the received shock from a typical mains-powered electric fence (powered by energizer units ranging from 18 to 40 joules). However, few cows receive the maximum pulse; most receive one that is less than half the maximum strength.

The energy of the pulse is set to the lowest level that will dissuade a cow from ignoring the sound cues, if it is set any lower, they ignore it.

Customising the pulse for individual animals

The delivery of the pulse depends on each animal’s response to it. The system customises the strength and frequency of the pulse to each individual animal’s tolerance and determination to push boundaries. There are multiple layers of product safeguards that protect animal welfare and that prevent animals experiencing excessive shocks including time-bound limits and daily maximums for the number of pulses.

For most of the year, while grazing pasture, trained animals rarely ignore the primary cues. When they do ignore the primary cues the vast majority only receive a single shock at the lowest strength in order to be safely and effectively contained within the boundary. A very small proportion of animals are resistant to the weakest pulse. We know from monitoring their behaviour that these animals fully understand the system. These animals require a higher energy shock and/or several shocks for safe and effective containment.

During the dry period when farmers constrain cow feed for health and welfare reasons3, and when cows feed on crops, they are more motivated to push boundaries and so most cows experience more frequent shocks than during the rest of the year. However, even during this period, most cows continue to only require the lowest energy pulse to be safely and effectively contained. Shock frequencies rapidly decline in the Spring and return to base levels when cows return to the milking herd. 

Customising pulses based on an animal’s historic behaviour is a critical feature for animal welfare, given cows have different thresholds to push boundaries. This feature is consistent with the recommendations from the UK’s Animal Welfare Committee’s opinion on the welfare implications of using virtual fencing systems (see section 5 of Halter’s Animal Welfare Charter).

Use of aversion to manage stock

Managing livestock on any farm requires the occasional use of aversive cues to contain and shift them. Aversive cues are varied and include: humans shouting, clapping and waving arms, the use of rattles or sticks, dogs, motorbikes, electric fences and even drones and helicopters. These aversive techniques are calibrated to the most resistant animal, so most animals in the herd will experience excessive fear and reduced animal welfare. Instead, Halter uses the least amount of aversion necessary to contain or move each individual animal. Any less and they ignore it. We have designed the system to give highly predictable and controllable cues as these have also been shown to be less aversive (Kearton et al., 2020). The Halter system uses an electric pulse as an aversive cue because:

  • It is adjustable - the energy can be customised and reduced to the absolute minimum necessary for each individual animal; and
  • It is designed to be highly predictable and avoidable.

Furthermore, the Halter cues are consistent. Every day the cow is guided with the same primary cues (sound and vibration), as opposed to the wide range of conventional cues which can vary considerably from day to day, for example across different farm staff, farm dogs etc. Cue consistency is essential to predictability and therefore efficiency of outcomes achieved and to the animal retaining control of its actions.

Ongoing product refinement 

A core animal welfare safeguard is that the system uses the least amount of aversion necessary to safely contain and manage animals. The amount of aversion needed will vary depending on the animal breeds, grazing systems, and seasonal factors. The technology adapts to this. Currently the maximum energy of a single pulse delivered by the Halter collars is 0.18 joules. Future generations of the collar may have different limits as Halter scales to serve farms across different animal breeds, grazing systems and markets. Ongoing research and development optimises the most effective delivery of the pulse needed to safely manage animals, while protecting animal welfare. We are constantly monitoring our animal performance data to make system enhancements that improve animal welfare.

Halter also works closely with an independent animal ethics committee when undertaking research and development that has animal welfare considerations. We remain committed to transparency about our product and sharing context with our users and the public, and will provide more information as our system evolves.

Herding dairy cows vs herding beef cattle

Halter uses two different types of ‘shifting’ functionality to virtually herd cattle from one location to another: active shifting and passive shifting.

Active shifting (dairy cows)

To herd dairy cows, Halter uses ‘active shifting’. Dairy cows are already familiar with regular daily movements on farm, so active shifting is used to guide dairy cows to new pasture breaks or from the paddock to the milking shed. Sound cues are used to head the cow in the correct direction and vibration cues to encourage forward movement. If an animal ignores the vibration cues to move forward with the rest of her mob,, after an extended period and only once the cues have escalated, she would then receive a shock to reinforce the primary cues and encourage her to keep moving. If for any reason she cannot keep moving forward, the system will disable and pulses will stop.

Passive shifting (beef cattle)

By contrast, for beef cattle the Halter system uses ‘passive shifting’, which accounts for differences in behaviour and temperament of beef cattle breeds compared to dairy breeds. Passive shifting allows animals unconstrained time to move to their next pasture allocation. When they are being passively shifted, cattle receive directional sound cues and then a vibration cue once they are facing in the direction of the next allocation of feed. This vibration cue is never reinforced with an electric pulse. The virtual boundary between the old and new pasture allocations becomes activated when the majority of cattle have crossed the boundary, to prevent cattle returning to the old break. It is only activated for those cattle that have already crossed the boundary. Their natural social desire to be with the rest of the herd draws the rest of the cattle into the new allocation. 

Halter’s virtual herding does NOT use a ‘roaming’ virtual fence to ‘sweep’ cows into a zone from behind. This is a somewhat common misconception about virtual herding. Instead, cows receive individual guidance cues at the same time, and these cues are customised per animal based on their location and heading. All animals are allowed to move in their own time.

²  Tasmanian Institute of Agriculture - ‘Managing dairy cows with Halter virtual fencing technology’, Dr Megan Verdon (preliminary study results, September 2023)

3  Such as stopping milk production by constraining protein intake and managing pre-calving BCS to avoid metabolic disease.