Answer:
I think you're referring to the sport of cutting with horses. Cutting is a Western event that originated on the ranches. A horse and rider are put into a pen with approximately ten cows. They must then separate certain cows ("cut" them from the herd) and keep them away from the herd for a length of time. Top horses in the cutting world are able to do almost all of this on their own; the rider simply lets them know what cow to go after and the horse will do the rest. The horses will also anticipate the movements of the cow; a horse who can do that is said to be "cowy" or "have cowsense."
That's my answer!
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