Ornua has vowed to fight accusations of “false and misleading advertising” after a class action lawsuit was filed against Kerrygold in the US contesting claims its cows are grass-fed.

Californian Dyami Myers-Taylor has filed a suit against Ornua North America and parent the Ornua Co-op, after accusing Kerrygold of also feeding its Irish cows corn, soya and GM feeds.

He claimed he paid a premium for Kerrygold products on the understanding cows were exclusively grass-fed.

In response, Ornua said it marketed its product “in accordance with applicable laws and regulations” and would “vigorously defend claims which propose otherwise”. The brand’s website claims almost 85% of its cows’ diets came from grass, supplemented by grains during winter”We believe our products are marketed in accordance with applicable laws and regulations and will vigorously defend claims which propose otherwise,” said an Ornua spokesman.

Kerrygold’s marketing activity in he US is heavily focused on its cows’ grass-fed credentials, with the brand’s US portfolio featuring a strapline which reads ‘milk from grass-fed cows’. The brand achieved double digit volume growth in the US in 2017, contributing to Ornua’s 18% revenue growth to €2.1bn.