From the heading, it looks like it came from that prolific songwriter, ould Turlough Anon. From the style, I'd trace it to the County Offaly. / Jus' kidding Guest Taffy. Dunno.

But it's the selfsame principle as in that sad tale of the 3 travelers, an Israeli, an Indian, and an Irishman, who come up to a farmer's house seeking lodging for the night. The hospitable farmer invites them in, saying "I can put up two of you but haven't the room for 3, so one will have to sleep in the barn." Drawing lots, the Tel Avivian loses, so it's off to the barn with him. 1 in the morning comes a knocking on the farmer's door: yer man. Says "I'm sorry to disturb you but there's a pig -- treif! -- sharing my bed of hay out there and it is against my Jewish religion to repose in proximity to an unclean beast." So the humble Indian fellow volunteers to take his place. 2 a.m., knockin' on the door. Says the sleepless subcontinental feller: "I'm very sorry indeed, but there is a cow in the barn and a Hindu must not recline near to a sacred ancestor." "Arrah th' Pope, Gawd bless 'im, has no such regulations at all, at all," says Paddy, "an' d'ye know what I'm goin' t' tell yez, it's the barn fer me an' a good night to all." 2:15, a mighty battering and roaring at the door. Yes: the cow and the pig. :)