Some people think that "8 maids a milking may be a corruption of "Eight maids a-maukin" which would be hunting hare for the Christmas feast.

Given that many dairy cattle would be "dry" at this season of the year, or giving very little milk, needing 8 maids to milk would have required a VERY large dairy herd. Thus the possibility that they were hunting small game (probably with some kind of a hawk) makes sense.