Whatever works for you and the guy down the road with cows……You basically want to do graze/rest…..graze/rest cycles………The amount of time for each is something you’ll learn to eyeball based on the rate of stocking…… What you don’t want to do is turn so many loose and leave them in there so long they that they turn it into a worn out pasture. You just want them to keep the vegetation in early successional stages.