whats the best way to cattle break a dog

Thanks for all the responses, I have used the Tritronics to break dogs off deer with some success. The dog I am refering too is almost two and hunts like you wouldnt believe and has been finding hogs out the box on every hunt if they are anywhere around and gets alot of praise and knows she is doing the right thing. She just likes cows. Want put teeth to them but will bring in a stray and put them bck with the herd and circle them up quick if we happen to get too close to a pasture which we do very seldom. I dont have cows myself but a friend has one he is feeding out in his pasture so i will give it a shot with it. thanks again. let you know how it goes.