His father and grandfather were both at the helm of dairy companies in the days when dozens of co-operatives were scattered throughout rural New Zealand.
His grandfather chaired the Newman co-operative company in the Eketahuna district and his father Jack chaired at least five co-operatives in our district.
The Mongahan family have a proud 110-year connection with the Eketahuna community.
"I take some pride in having farmed all my life,'' Monaghan told the Dannevirke News.
"We were talked about as the sunset industry in the 1980s and told to put fences around our properties for horticulture.''
Monaghan has been closely involved in the process to appoint a new chief executive to Fonterra and will now lead the advancement of this appointment with the full involvement of the board.
Kieran McAnualty, Labour List MP based in Masterton, said he's delighted Monaghan has been appointed chairman of Fonterra.
"Fonterra plays a crucial role in the New Zealand economy. Its leadership over the last few years in transitioning away from volume to value and environmentally sustainable production contributes significantly to how New Zealand is seen by overseas consumers.
"In many ways Fonterra has paved the way for other New Zealand companies. And, John has played a leading role within Fonterra over this period.
"It is just marvellous that the Tararua district has one of its own is at the helm of one of our most important companies. It is great for the dairy sector and for our region.
"And on a personal note, I'm pretty stoked to see a cousin of mine achieve such a feat. And so is the rest of the family.
"I'd also like to acknowledge the role John's wife Sarah has played in supporting him to this point."
McAnualty, who is on the Primary Production Select Committee and chairman of the Labour Party's rural caucus, said he was looking forward to working with Monaghan.
In a message to farmers, outgoing chairman John Wilson said the decision to stand down had been difficult but was ultimately in the best interests of the co-operative.
"I have made a very good recovery and am well but will need on-going treatment," he said.
"It has been a privilege to serve as chairman and give something back to this great co-operative that continues to give my family and me so much.
"Continuing as chairman when I cannot put my full energy and attention into the role is not appropriate."