You attend the party?
I'm pretty sketchy on French language, but got puzzled how milk (lait) was part of the phrase.
Oh, milk fed (suckling) pig is the translation.
I got educated on whole hog cooking while in college. Vet med student and a German family taught me the proper method to start the process. Select, kill, scald, scrape, gut, and chill.
Parochial school my children attended has an annual (whole) hog roast fund raiser.
I miss the cracklins. None of the live kill lockers around here leave the skin on a hog. Lazy buggers.