We have a "real cow" mechanical cow for sale or trade. I have had it about two years and used about a dozen times. It runs  independently so you can move it toward or away from your horse and not just back and forth, you can move it anywhere in the arena with a remote like you use for a flag.   They are true robots and are pricey at $25,000 new which is what I paid two years ago. 

It could be shipped freight on a pallet (that's how I received it from South Carolina). The link is where you can see it in action at the manufacturer's website and cutting horse training online...