Ensuring the environmental sustainability of their farming business led to a system change on a 1000-cow Southland dairy farm. Mitchell and Kate Johnston have just finished their seventh season on a 613-hectare farm at Hedgehope inland from Invercargill.

“My parents originally hailed from Taranaki, moving to Southland in 1990,” Mitchell said. “When they moved here, the farm was 350ha milking 800 cows. Over time two neighbouring properties were added generating the current 614ha property.

“Kate and I purchased the farm in 2012 and the additional land has enabled the milking herd to increase to 1000 cows and a move to a self-contained high-input farming system.

“Environmental and animal welfare considerations led to the system change. Rather than milking more cows, we wanted to take better care of our stock. As we improved our farming knowledge and developed better systems and understanding of cow nutrition the performance of our stock improved, resulting in significantly better per cow performance.

“As the per cow performance increased, it soon become apparent that the genetics of our herd were not keeping pace, with a number of animals needing to be culled with structural issues, mainly poor udders.

“We had been considering options of introducing overseas genetics to help fix these issues and were fortunate to come across some surplus stock from a well-established World Wide Sires herd.

“Boy did we notice a difference when we introduced and compared the new cows with the herd we’d brought with us from Taranaki. They were like chalk and cheese. The World Wide Sires cows had fantastic udders and milked like trains. We didn’t have a second thought and changed the entire breeding programme that spring to World Wide Sires and haven’t looked back.

“The change has paid off. When we took over the herd, they were averaging 400kg per cow. Seven years we hit 645kg for the 2019/20 season.

“Moving away from BW didn’t worry us. We need cows which will see us into the future. Our top cow is a case in point. She consistently produces in excess of 1000kg MS yet her BW is -98. By contrast, most of the cows we used to cull for poor udders had very high BW.

“For the first few years with World Wide Sires, our sire selection was based on udders. But now we are focusing more on production and other traits.

“It’s a tough job now finding a cow to cull – they are so consistently good.”