A European Union diplomat says EU farmers cannot be blamed for low farmgate milk prices.

Trade minister Todd McClay says he's received strong assurances that New Zealand's trade interests will not be adversely affected as a result of the Brexit vote.

Food fraud is estimated to cost the global food industry $US49 billion a year, with New Zealand companies bearing their share of the brunt.

The more varied offering at this weeks' South Island auction saw targeted buying with better demand for the longer wools.

Every imaginable commentator has come out of the woodwork to offer their two cents worth on Brexit – Britain's exit from the EU.

Maersk Line, the world's largest container shipping company and Kotahi, New Zealand's leading export supply chain collaborator, are set to welcome the largest container ship to ever visit NZ waters.

Trade Minister Todd McClay says outcomes of the G20 Trade Ministers' meeting held in Shanghai July 9-10, are likely to be extremely important for New Zealand's trade interests.

Dairy farmers will need more time to upgrade milk cooling systems to align them with proposed new regulations.

The GlobalDairyTrade (GDT) price index fall of 0.4% last week was "modest" in the face of Brexit's impact on other markets, rural economists concur.

Trade Minister Todd McClay will take the opportunity at this weekend's G20 Trade Ministers' Meeting in Shanghai to promote New Zealand's trade interests with the biggest economies in the world.