A cow wearing a Halter solar-powered collar stands in a green field, the collar visible around her neck with its GPS and sensor hardware

A Peter Thiel-backed startup called Halter makes AI collars for cows. It’s now worth $2 billion.

Every cow wears a solar-powered collar that talks to a network of radio towers and an app on the farmer’s phone. Instead of building physical fences, the farmer draws the fence on a map, and the collar keeps each cow inside the invisible line using GPS.

When a cow drifts toward the edge, the collar plays a sound; a gentle vibration tells her which way to go – like a car beeping as you back up toward a wall. The cows learn the cues in a few days. A rancher can move an entire herd to fresh grass by sliding the fence on the map, without driving out to open a single gate.

An aerial view of a herd of cattle shifting position in response to a virtual fence update, the herd moving as a group across open grassland

The same collar monitors the cow for vital signs, and can discover sickness, injury, breeding readiness, or imminent calving before any person walking the field would notice.

The Cowgorithm AI is trained on more than 7 billion hours of real cattle behavior. Halter knows how normal cows behave better than anyone, so they can flag the odd one out instantly.

The product is deployed on more than 1 million cattle across New Zealand, Australia, and several US states. California even uses Halter to graze cattle in patterns that clear dry brush and slow wildfires.

For $5-$8 per cow per month, Halter changes a task that required miles of barbed wire, gates, and driving the fields all day into one that can now mostly be done by one person on their phone.

The Halter app on a mobile phone showing a map of farmland with virtual fence boundaries drawn and individual cow locations marked