Hand feeding a litter is one of the most anxiety producing moments in a rabbit breeders life. If the doe dies during kindling, and you have no doe available to foster the young to, then you must try to hand feed the litter.
These are some tips I have learned on my own, from other people, and from reading rabbit literature.
Most often if you have a doe and you suspect that the doe is not feeding the litter, try holding the doe on your lap(you will need as many helpers as you can get) and let the kits nurse, I always let them nurse until they lose interest, or aren't hungry anymore, this may be 10 minutes. *Check the kits belly, if it is round and full, then you can keep holding the doe in this manner until either the doe resumes taking care of the bunnies, or else the bunnies start eating pellets (3 weeks). If the bellies are flat, and the skin is wrinkled, then the kits are not getting any milk, and you will have to feed them a substitute formula.
You need to feed the kits approximately every 6 hours for the first 2 weeks, then every 8 hours the 3rd week, then every 12 hours the 4th week. After that the bunnies should be able to eat pellets, I also give some quaker oats to the bunnies.
Of course, if you are holding the doe, and letting the bunnies nurse, then you should feed the bunnies only twice a day.
The next few paragraphs are the important parts. Feed the bunny in an upright position with an eye dropper or a syringe (with no needle), it will take a few days for both you and the bunny to get the hang of it, but it will work. I have never had much luck with the pet nursers (bottles designed for orphaned kittens/puppies) but I would think that it would work better if it works for you. If the bunny starts sneezing, choking, or coughing during feeding, you need to give the formula slower, the biggest problem with hand feeding orphans if aspiration pneumonia--that is where the bunnies get some formula in their lungs, and it causes pneumonia, which will probably kill the bunny. I have had many bunnies, that have choked while feeding them and lived, so if this happens, do not be too hard on yourself right away!
You must stimulate the bunnies to urinate after every feeding! I have had good luck with a cotton ball and warm water, you wipe their belly and genitals, like the doe would after each feeding, sometimes this takes 10 minutes before the bunnies would go. It is helpful if you have a large litter to get someone else to help, you can feed one, and the helper can wipe the bunnies.
Hand feeding a litter is extrememly stressful on both the bunnies and you, mistakes will be made, some bunnies will not live no matter what you do, but I have a very spoiled Himilayan Buck right now, that i'm very happy he put me through all the trouble. He was what you would call a "fader" a bunny that is weaker than the rest (similar to failure to thrive in humans), and gets weaker and weaker, as his littermates get bigger and stronger. Now he is 4 1/2 months old, and he is heavier than some of his brothers! When I was desperately searching for suggestions on how to take care of this little "himi fader" I had, I got an Email from a lady who has hollands, she told me that in the Holland Lop guidebook there is a formula for feeding orphaned bunnies, from 13 days and up, and that is to feed them Gerber creamed spinach, with a syringe, she said that the bunny would spit it out the first time, but to try again in 10 minutes, and the bunny would eat it up, I couldn't get my then 8 day old himi to eat it. But it would be good to know about nonetheless.
When the bunnies are 2 weeks old, I start giving them their milk in a shallow plastic lid, they learn to drink from a bowl in about 2 minutes. I also make sure that they have pellets available from 2 weeks on also.
