Lakeland Dairies' line of VIVA flavoured milks is part of the largest shake-up of McDonald's Happy Meal range for more than a decade.
McDonald's has selected Lakeland's no added sugar VIVA range of 200ml chocolate, banana and strawberry milks to be a key part of the new menu.
The trial will run for 14 weeks, starting on Wednesday May 29, across 180 restaurants in the UK as well as seven restaurants in Ireland.
Today's deal builds on the long-term relationship between McDonald's and the co-op - Lakeland's Milk Stick has been a mainstay in McDonald's for many years.
Lakeland currently processes around 2 billion litres of milk produced by 3,200 farm families on both sides of the border.
Colin Kelly, Lakeland Dairies' Group CEO, said the co-op was excited to partner with McDonald's on the revamp of their Happy Meal menu.
"We are proud that the milk produced by our 3,200 farm families will be enjoyed by children, young and old, as part of this development," he added.
