He drew a fence. The cows obeyed. A New Zealand farmer used his phone to draw a virtual boundary — no physical wires, no fencing crew. 200 cows haven't stepped past it all day. This is the Halter Collar, a GPS-enabled collar that sits on each cow's neck and builds an invisible fence using sound, vibration, and a tiny pulse. Here's how it works: → Cow approaches the boundary → soft beep → Ignores the beep → gentle vibration → Still pushing forward → small electric pulse → Within one week, cows learn to turn back at the beep alone But the real unlock is the AI brain behind it — called Cowgorithm. It's trained on 7 billion hours of cow behaviour. It tracks each animal individually, flags illness before symptoms appear, monitors fertility, and measures exactly how much grass each cow eats — all in real time. Traditional paddock fencing costs a US farmer $2,000–$10,000 per acre. Halter makes that entirely unnecessary. Over 1 million collars. 3 continents. $220M raised. $2B valuat...