How much grain to feed my lamb!!?

I raise pigs for FFA, but i have close contact with the lambs in the barn. My friends feed their lambs between 1-2 lbs of feed twice a day. The amount fluctuates due to the amount of weight the lamb gains from the feed. Our instructor will cut the feed if the lamb's fat stores are too "fatty", and will increase the amount of feed if the lamb lacks muscle tone. If you exercise the lamb often (at least everyday) then he'll need more feed than usual to make up for the energy he expends running around the pasture. I hope this helped a bit :)