Darley & McCall's "Feis Ceoil Collection of Irish Airs" (1914) affords a very nice version of the tune, titled only "Im Bo (Milking Song)":

http://www.tunearch.org/wiki/Im_B%C3%B3

It was "Played by Brian Mac Intyre, fiddler, Virginia, Co. Cavan." The editors observe that "There must have been an old Gaelic song sung to this air (Im, butter; Bo, a cow)."

D & Mc began collecting in 1897.