We have 3 1/2 acres of pasture we work off of here in southern Texas. We just purchased our first bred heifer that will be pastured with our 3 horses. We feed our horses each 4 flakes of hay per day (we are in a major drought and there is no grass) and maintenance feed for the two adults and 8 pounds of feed per day for my growing yearling. Our heifer is also getting 4 flakes of coastal hay per day, 4 scoops of Purina Show Chow, a scoop of cattle cubes, and the grass in her pen. Since we are working off a small piece of acreage, we will be constantly feeding additional feed and hay. Our size of property cannot support our animals on the grass it grows alone. If you are working on a small homestead or even a bit larger but with little grass, be prepared to have to feed and hay your cow, no matter what size it is.
I hope this helped