Much of our "cowboy culture" is rooted in the Vaquero traditions and culture of Latin America- and of the American west as well.
Because of the connections of the song with a group from the British Isles, I have not really looked for the Irish-Latin connection, but it could have happened that way. I had one g-g-grandad from Ireland who settled in New Mexico and who worked the cattle drives to Montana, often working with Spanish-speaking cowboys in part, but this was in the Civil War period and shortly thereafter. Spanish-speaking traders from Santa Fe worked the routes of the Santa Fe Trail from Missouri and the Chihuahua Trail to Mexico along with the Anglos.

Apart from this thread, but of possible interest to you, if you haven't seen it before, Sorefingers, is this site devoted to the vaqueros of the American-Mexican southwest: Cowboys-Vaqueros

If you have any songs, or information about possible Spanish versions, I would be glad to hear of them.