You can get Kerry Gold and Yeo Valley Organic butter from tesco, both of which are grass fed.

I would firstly say that overstressing grass-fed when it comes to butter (or even beef - "A review of fatty acid profiles and antioxidant content in grass-fed and grain-fed beef") can be counter productive, meaning you are OK even if your butter isn't grass-fed.

That being said, my experience is that Europe hasn't gotten into the whole grass-fed movement yet and therefore products with that label can be harder to found.

One option is to e-mail the producers/importers of the product although from my e-mailing ventures, some are really generous with the data (like one company even sent me lab analysis) while others don't even repy but still, give it a go, you never know what might happen.

The second option are farmers markets where you basically go around and aske farmers about how the product was raised.

Or try googling "raw milk" or eco-milk, organic milk (in Slovakian) to get some contacts to the farmers.

Good hunting.

If you are from Slovakia, you don't have to worry about KerryGold, Slovak butter won in blind test competition:) KerryGold is salted anyway...

http://hartkeisonline.com/travel/taste-of-slovenia-a-real-food-tour/

WAPF western price people make a food tour in your neighbour country. so probably you will find something there. or go ro the WAPF hompage and look for local chapter.

There should be someone. look for slow food and organic or drive to the countryside where cow are on the pastures.

http://www.ecotrend.sk/

Somewhere on the packaging should be an oval mark. The first 2 letters indicate the country of origin. For a list, go here

The next numbers show which establishment made the product.

The last 2 letters can be ignored (CE, EC, EF, EG, EK, EO, EY, ES, EÜ, EK, EB or WE).