Ornua has responded to what it said are "misleading claims online" about its Kerrygold butter which are "confusing or concerning".
Recent posts from social media accounts, believed to be based in the US, have focused on Kerrygold's "grass-fed" branding and the origin of supplementary feed given to cows.
"We are aware of recent misinformation circulating online about Kerrygold.
"While open discussion is welcome, the spread of misleading or inaccurate claims to do with our products is something we take very seriously," a spokesperson for Ornua told Agriland.
Kerrygold is the second most popular butter brand in the US.
In response to the online posts, Ornua has published a notice for consumers on its Kerrygold website.
"We believe the best way to build a relationship of trust with you is through transparency and accurate information.
"That is why we share clear, verified details about our products directly," the website states.
The Irish dairy co-op said "Ornua buys milk for its Kerrygold products from its members, who in turn, buy all their milk from farmers in their area".
The website outlines that Ireland's "temperate climate, abundant rainfall and tradition of family farming have resulted in a grass-fed system with typical Irish dairy cows grazing outdoors on rich grass for the majority of the year".
"During Ireland’s winter months and during bad weather conditions, a typical Irish dairy cow still enjoys a predominantly grass-based diet.
"They eat silage, which is fermented, high-moisture fodder cut from summer grass and stored for winter feeding.
"Throughout the year, to ensure optimum health of the animals, a typical Irish dairy cow’s grass-based diet also includes a very small amount of supplementary feed.
"This is used to give the cows a healthy and balanced blend of nutrients, providing them with protein, energy, fibre and micronutrients," the website adds.
Ornua said it is a verified member of Bord Bia’s Origin Green food and drink sustainability programme which includes the Sustainable Dairy Assurance Scheme (SDAS).
"The SDAS is Ireland’s national dairy scheme setting out practice on Irish dairy farms in the areas of animal health and welfare, land management, biosecurity, safe farming practices and the production of safe milk," the co-op said.
Ornua told Agriland: "Our brand is built on trust, transparency, and the exceptional quality of Irish grass-fed dairy".
"Behind that quality are hardworking Irish dairy farmers whose dedication and commitment to upholding the highest standards in grass-fed dairy farming deserve to be fairly represented.
"We will continue to represent and champion what our farmer suppliers do and address inaccurate claims," the spokesperson added.
Agriland also asked Ornua to comment on other recent social media posts questioning the appearance, taste and consistency of Kerrygold butter.
“We have not changed our recipe or how we make Kerrygold. The only ingredients (for our salted butter) are cream and salt," the Ornua spokesperson said.