At Cow-Shed we love cow based Startups, and we are particularly impressed with Halter.
Halter is a fantastic new way of moving and managing cows using solar powered collars and a mobile app. Farmers use Halter to guide their cows around the farm - moving them between fields (and even virtual fields using virtual fences) and can call them into the shed for milking. The tracking view shows farmers where each of their cows are and lets them keep track of their cows welfare by letting them know when they are poorly.
This sounds an amazing way of reducing farmers workload - reviews from farmers are great so this looks like the future!