Glanbia shares slid 7.5%, stripping around €300m from its market value, as investors showed disappointment at the company’s 2018 earnings outlook, despite it unveiling 2017 figures which showed an eighth successive year of strong growth.

Glanbia is on course to deliver on its 7%-10% growth forecast for 2017, with revenues for the year to September 6.6% higher than this time last year.

Glanbia said the popularity of health and sports nutrition products such as whey protein powder will fuel growth in the coming months, as its global cheese production helped raise its revenues almost 10% to over €2bn in its first half results.

Farmers have given a cautious welcome to Glanbia’s plan to sell 60% of its Irish dairy business to Glanbia Co-op, creating a new Glanbia Ireland joint venture in a deal worth €112m.