Well kiddo, ó duibh dá bhoireann is actually a phrase in Irish Gaelic, which is one of the languages spoken in Ireland. It means "from two of your cows."
Imagine you have two cows on your farm. If someone wanted to say they got something from two of your cows, they might say "ó duibh dá bhoireann" in Irish Gaelic. It's just a way to say where something came from!
So basically, it's just a phrase in a different language that means "from two of your cows."