My father ran a dairy farm with his uncle, ~160 acres owned plus another 40 - 60 they rented. I think the most they ever milked was around 80 animals, this was back in the 70's.
I rent a house on a dairy farm of similar size now, but in a few months will be moving out and into the farm house my grandparents were in, where my father grew up. The farm land now belongs to my father's cousins, but we might be looking to buy it off them. The development rights were sold to the state (MA) under an open space protection plan. It's probably 65% open land, leaving roughly 50 acres of wooded land plus fence lines. Plenty of wood to burn and sell on the side. Probably make square bales off the hay fields. The horse people around here are paying as much as $7/bale delivered, and with the land we could rent around here, we estimate we could probably put up 20,000-25,000 bales/year. Should be interesting.