The decision followed the start of a recovery in world markets for dairy products following a prolonged slump that plunged milk producers into their worst income crisis in a generation.
Earlier, the Irish Dairy Board decided to increase its payout to co-ops for skim milk powder and butter products sold in September by the equivalent of 2.1c/litre.
Farm leaders have now called on Glanbia and other co-ops to pass on the increased commodity price rise to suppliers.
Dairygold chief executive Jim Woulfe said with dairy commodity price now beginning to strengthen in international markets the society had moved quickly to pass back the benefit.
“The decision on a September milk price increase has been taken in the cautiously optimistic belief that gradually improving dairy market returns will carry through into the coming year, but there is still a lot of uncertainty in the market.”
Mr Woulfe said the euro exchange rate has strengthened against sterling and the dollar, pulling back returns from international sales.
“Dairy farmers have experienced severe loss-making hardship in the current year and it is essential the Minister for Agriculture and Government continue to exert their influence to best possible effect to help strengthen markets and underpin a return to viable milk production,” he said.
IFA president Padraig Walshe said he been in contact Glanbia chairman Liam Herlihy, and left him under no doubt the group must immediately review its decision to merely hold its September milk price, and pay a 2c/l milk price increase.
“With Dairygold increasing the September milk price by 1.75c/l, Lakeland by 1.25c/l and Town of Monaghan by 1c/l, surely Glanbia board members cannot put the interests of the plc before those of their hard pressed suppliers,” he said.
IFA Dairy Committee chairman Richard Kennedy said a 2c/l price increase for September milk would be worth around €600 for the average supplier.
ICMSA deputy president John O’Leary said there is now a clear basis for co-ops who have set their September milk price to review their decisions.
Those yet to set the price must include the increased returns in the milk price paid to farmers, who are under enormous pressure and cannot wait another month.
Specifically calling on Glanbia to change its decision not to increase the September milk price, he said the ICMSA is seeking a back payment of 2.1 cent per litre for milk supplied in that month.
Glanbia, the largest processor in Ireland, was the first to lead milk price down when markets were deteriorating and must not be last to raise it, he said.