Some count their brood and show stock only when discussing how many rabbits they keep, others count up all the kits.
80 rabbits could easily be:
10 breeders, and 8 litters with 8 or 9 kits each.
So the maintenance for 80 rabbits wouldn't necessarily be as nightmarish as it seems, because most of them will head to freezer camp or new homes well before nail trims or any brushing is necessary.
There certainly are commercial raisers with 80+ brood does though. Meat stock may require no brushing, but I do wonder how they handle nail trims for all those adults. :?
To be honest, it seems that neglecting rabbit feet altogether isn't uncommon.
I have been to a few rabbitries now where nails were never cut.
I've also seen injuries on rabbits feet from such overly long nails catching on things and ripping off, or permanently
bent toes with nails grown upwards, which seems to happen when never cut nails are kept on a hard wooden surface.