Beef farmers have blockaded Musgrave's central distribution centre in Kilcock, Co. Kildare.
It started at 7am this morning and follows similar action at Tesco, Aldi and Lidl distribution centres in recent days.
Musgrave is the parent company of SuperValu and Centra.
The Irish Farmers' Association (IFA) said beef farmers should not accept the current beef price on offer from the factories.
John Coughlan - who is Munster Regional Chairman of the IFA - claimed farmers deserve better.
Speaking on Newstalk Breakfast, Mr Coughlan said: "Every euro that goes into farming in rural Ireland contributes [over] €4 to the local economy... that is critically important to rural Ireland."
Meanwhile, IFA President Joe Healy said today's 12-hour protest in Co Kildare suggested beef prices are "well behind" export benchmark prices.
He argued: "Irish farmers should be getting a higher price for their stock, supplies are tightening and farmers should hold out for more.
“Factories should increase prices today and we are driving home the message to retailers: Tell your suppliers to treat farmers fairly."
