Around 400 grain farmers have taken part in a protest outside the Glanbia headquarters in Kilkenny.
The Irish Farmers Association, which organised the demonstration, says growers stand to lose money as the price being offered for grain is below cost production.
Farmers have reacted angrily to Glanbia's grain new price plan, saying that it is unviable and unrealistic.
The spokesperson said there must be an overhaul of the current pricing mechanism.
