Day 28. I believe that's what the overall concensus was both on websites as well as forums when I first started researching raising rabbits. Then it just worked. I've only had 1 go earlier. My rabbits are nearly always 31 days on the mark no matter what breed.
I placed my nest box in about a week before delivery.
This was my rabbit, Lexi's, first litter, so she could build a first few nests to get used to it. Every time we had to clean it out, we felt bad. So I recommend putting the box in about four days early.
Oh, and say hello to my 6 new popples, born before lunch! :lol:
I put my does into the maternity "ward" when I palpate and feel the grapes at 14 days. If I do not feel the "grapes" I wait another week before I move them to see if I can feel the kits then. Or else I just wait till they begin haystaching their daily ration then provide a nestbox.
My rabbits are outside under lean to type shelters, so I leave nestboxes in all cages year round to provide extra shelter. I have only had one or two rabbits ever decide to use them as litter boxes, so I've been pretty lucky that way. The does just start building when they are ready.
All my rabbits get a handful of hay every day. When a expecting doe starts to make a nest with her hay I put the nest box in. Roxie usually starts around day 21. Margo usually more like day 27. At any rate I pretty much let them tell me when they want a nest. I don't know if its the best method but has worked out so far.
I have a large plastic storage box with a hole cut out available at all times. Never had a doe use it for a potty *yet*. Most times they just lay on top of it
One week before they are due, I change out the straw. Never had any kits born on the wire *so far*