If the land is well fertilized, and since you say the owners are organo-philes, it more than likely is.... as long as the grass is growing fast enough to meet their needs, they may be OK... If they are bringing in hay because there isn't enough grass to go around, you may be right that it is over stocked. Are the animal staying with the farm, or moving up with the current owners? One of the benefits of buying land that is already being used for cattle, is that your fence building will be minimal... The land I am on had no fences, so all of the fencing we have has been put in by me... what fun THAT is! I will admit, diggin post holes is a grat shoulder work out!