Old McDonald had a farm. The company managed by his descendants is now the 14th-largest private landowner in the world. Hold your ee-i-ee-i-o’s: This is not the farmer of nursery rhyme fame. That apocryphal MacDonald probably was inserted into a traditional folk song in early 20th-century America. These McDonalds (without the interstitial “a”) have been farming in Australia since 1827, when the first cattle were shipped to Tasmania. A Cattle Empire In 1947, Jim McDonald purchased Brightlands Station, a vast ranch in the state of Queensland. In the decades since,…