Milk collected from the company's 1000-plus farmers in the North and South Islands was up 1.6 per cent. Product tonnage turned out lifted 2.6 per cent.
Margrain said the bottom line was boosted by a reduced foreign exchange expense, which fell from $15.9m to $2.3m.
Commenting in the 2020 annual report, Margrain and chief executive Steve Koekemoer said Covid-19 created significant periods of uncertainty in market demand, supply chain efficiency, currency trends and put operational performance under some stress.
With the company's latest manufacturing expansion at Awarua, Southland only coming online at the end of the financial year, Open Country had operated with little change in its processing capacity in 2020, they said.
"With all plants at total optimum capacity for the peak supply periods in each region there has been extremely limited opportunity to add to our milk collection volumes. Litres of milk collected were slightly up at plus 1.6 per cent on the previous year, albeit that does not reflect the inherent demand that still exists for suppliers to join Open Country ...
"Again, due to operating at capacity tonnage produced was only marginally up at plus 2.6 per cent."
Market demand and product mix had enabled the company to pay "very competitive" milk prices to its farmers, who unlike suppliers to industry leader Fonterra, do not have to buy shares to supply milk.
In the Waikato at least, Open Country scored higher on its 2020 financial achievements than its environmental performance.
In early September it was convicted and fined $137,500 for discharging odour that caused nausea, retching and vomiting for some in the Waharoa community near Matamata in 2019.
The company was also ordered in the Hamilton District Court to put $120,000 in a trust for the community as reparation.
It was the fifth environmental prosecution against Open Country in the Waikato.
During the year Waikato Regional Council also declined Open Country's resource consent application to discharge contaminants from the Waharoa site into the Waitoa River during summer. However, its application for air discharges was approved.
The company during the financial year commissioned a $20m wastewater treatment plan at Waharoa.
The annual report said this was a significant milestone in future proofing the site against any prospects of breaching its consents "and causing disruption to our local community there".
The company also installed at Awarua the largest electrode boiler in Australasia, using 100 per cent renewable energy and full water recycling capability.
No dividend was paid. Retained earnings drove net equity at balance date up to $526.4m from $458.8m the previous year.
Established after New Zealand's 2001 deregulation of dairy exporting, Open Country is 76.8 per cent owned by food company Talleys. Singapore's Olam International owns 15 per cent. It has manufacturing sites in the Waikato, Whanganui and Southland.
