It all depends on the breed of cattle and the area you live in. Some places are 1 cow to 1 acre others are 1 cow to 50 acres year round with no extra feeding.
If you live in a state that has rain most of the year and lush green grass then you'll have more cattle per acre than states that have sagebrush and little grass.
Irrigation or no irrigation. Snow 6 months of the year or no snow at all.
Maybe a little better idea of your area, weather, do you plan on feeding or want feed growing on the ground year young.
Are you talking about lactating and gestating females and a bull? I might have missed some of this info. I apologize if I have.
