Bovaer's fate

While many countries, including Australia, have approved the use of the feed additive, authorities in NZ are still grappling with allowing NZ dairy farmers to use it.

Controversy erupted just before Christmas, when BBC's Inside Science podcast reported on a social media backlash to well-known brands of milk, butter and cheese sold at major United Kingdom supermarkets, produced using milk from lower-methane cows.

After false rumours Fonterra was using the product, the dairy giant tweeted last month that food safety and quality were its "number one priority" and that Bovaer had not been approved for use on New Zealand farms.