I started doing intensive rotational grazing this year after years of continuous grazing. As a result of crossfencing my farm I found that I have a lot more pasture potential, with the cows being controlled verses going any where they want to. So I let some of my unneeded pasture grow up to seed then cut it down to about 8 to 10 inches, then let the cows graze it, then I cut it on down to about 4 to 5 inches....the residue that cows didn't eat. There is a whole lot of seed potential by letting it head out, but you probably need to make sure it pollinates or it won't germinate.