there is a longer version published in T. Ó Concheanainn, Nua-Dhuanaire III. Dublin: Institiúid Ardléinn / Institute of Higher Studies, 1978 & 1981.
sources given are Béal 914, 434-8; 'Amhráin ó Iorrus', Béaloideas 1C (1940) 258-60; An tAithriseóir 1(ediied by T Ó Donnchadha & P Mac Piarais, Dublin, 1900), 13-14.

From Ó Concheanainn notes I see that Tomás de Búrca collected the song as published in Béal 914, 434-8 and wrote that according to Séamus a Gionntaigh (age 63 in 1943) that Donncha Bán's sister composed the song . She blamed Mulchróin for stealing the horse and putting it on Donncha's land, so that Donncha was found guilty of the crime.

Mhíchíl Uí Ghallchobhair, who took down the 'Amhráin ó Iorrus', (songs of Erris, Co Mayo), said that in the summer of 1895, he happened to be on holiday in the state of Wisconsin, in a small town called Elroy. There were a good number of people from Mayo living in the area and he collected a version of Donncha Bán from them.