Mark Turnwald

Client: Mark Turnwald
Location: Ōhaupō, Waikato
Farm Size: 104 hectares
Herd Size: 360 cows
Structures Installed: Two composting barns (18m x 80m each)

Background

Mark Turnwald farms on a 150-year-old family property in Ōhaupō, in the heart of the Waikato. With deep roots in the region’s dairy industry, Mark is committed to long-term sustainability and profitability. However, like many in the area, he faces a unique challenge: Hamilton clay and consolidated peat soils, which, combined with wet winters, lead to significant pasture damage and limit productivity.

Mark recognised the need for a smarter, more sustainable solution that would protect his land, improve herd health, and offer a more predictable winter management system.

The Solution: Composting Barns for Wintering and Feeding

To address the ongoing winter challenges, Mark installed two composting barns, each 18 metres wide and 80 metres long. These barns now serve as protected wintering areas and feed pads for his herd of 360 cows.

“The cows are shiny and happy and fat in here. They are probably in the best condition we’ve had cows in during winter.”
– Mark Turnwald

The barns have become a cornerstone of the farm’s infrastructure — delivering multiple benefits across animal health, pasture protection, and operational repeatability for staff.

Key Drivers for the Investment

Mark’s decision to build shelters was driven by several goals:

• Profitability: Improving milk production and reducing feed wastage.
• Animal Health: Providing cows with shelter from winter cold, summer heat, and wet conditions.
• Soil Management: Reducing pasture pugging and nitrate leaching (Perrin report: 45% reduction).
• Staff & Routine Efficiency: Creating a consistent and repeatable system for herd and people.
• Peace of Mind: Reducing weather-related stress for both animals and farmer.

The Strategic Plan

To maximise the benefits of the barns and increase overall productivity, Mark implemented a broader farm management strategy:

• Lift stocking rate by growing more maize on-farm.
• Run more cows to capitalise on feed efficiency and barn use.
• Advance calving dates to achieve more days in milk.
• Undersow 30% of the farm annually to maintain pasture quality.

What We Learned

After the first season using the composting barns, Mark noted several learnings and results:

• Animal condition improved — cows entered calving in better shape and were protected from rain and cold.
• Calf survival increased due to calving in the barn.
• Colostrum management improved with better routines.
• Summer performance increased — reduced heat stress, more consistent production, and better pasture growth.
• Environmental outcomes were positive — less overgrazing, improved pasture recovery, and reduced nitrate leaching.

Conclusion

The installation of composting barns has significantly transformed operations on Mark Turnwald’s farm. From animal welfare and pasture protection to feed efficiency and environmental outcomes, the benefits have been tangible. What began as a solution to combat winter damage has evolved into a year-round system that supports productivity, resilience, and peace of mind.

Watch the video above to hear Mark’s story in his own words.