Glanbia milk suppliers face a drop in milk price of 2 cents per litre on all milk produced in the month of May this year.
The board of the GII announced a new base price of 37 cents per litre in recent days.
The previous price of 39 cents per litre had been a record high.
A further price reduction of 2 cents per litre is possible for the month of June due to falling dairy prices across the globe.