Arielle, the Kerrygold website has changed since I last looked at it. I couldn't find any information about grain-finishing.

The website states grass-fed butter. A few years ago, the website stated that sometimes, they would finish with grains. AFAIK, Ireland is non-GMO. I do not like these new websites that require so much scrolling and clicking. The old websites were very easy to read, at a glance.

Have you got a link or a reference for the grains?

If they are using grain-finishing all the time, that'd be a good reason, for me, to buy a 100% grass-fed butter.