The MacLachlans, one of the country’s oldest and most powerful farming families – and the nation’s third-largest landowner – are splitting up their huge portfolio of livestock stations in the biggest shake-up of their Jumbuck Pastoral rural empire in 135 years.

In a newsletter to staff circulated in July and made public this week, the family said brothers Jock and Callum would be leaving the business as part of a rationalisation of Jumbuck and due to succession planning.