Did some googling. From what I can tell, almost all cows in Ireland are grass-fed -- beef, veal, dairy etc. The industries there just aren't big enough to make the American CAFO-model profitable (thank goodness). However, many cows need grain-finishing in winter. My advice would be to stock up on butter in summer and freeze it. Then you're sure to get summer grass-fed butter.
5'0" female, 44 years old. Started Primal October 31, 2011, at a skinny fat 111.5 lbs. Low weight: 99.5 lb on a fast. Gained back to 115(!) on SAD chocolate, potato chips, and stress. Currently keeping food tracker.
I (try to) follow by-the-book primal as advocated by Mark Sisson, except for whey powder and a bit of cream. I advocate a two-month strict adjustment for newbies. But everybody is different and should tweak Primal to their own needs.