Rearing baby buns is sooooo tough. I've recently tried to hand rear a litter of 4 and only 1 survived
Personally I'd feed 4 times per day (every 6 hours).
People have had success with the following formulas for very young babies: Cimicat, Esbilac and Lactol Gold Kitten. However if the babies are slightly older, then goats milk is a good choice and very palatable (the formulas taste nasty...yes I've tried them
)
I would guess that quantity would depend on the age of the baby and also the formula. I found that they would take very little (about 3mls per feed) until the eyes opened, and then the quantites increased rapidly.
Hygiene is very important. Make formula up fresh for every feed...do not reheat milk/formula under any circumstances. Also sterilize all feeding equipment, or throw it away and replace with new at every feed.
Feeding equipment is quite a personal choice. It's best to use a bottle or 1ml syringe with a
Catac ST1 teat on the end (available to buy over the internet). However I couldn't get my babies to suck properly so I used a 1ml syringe with no teat and depressed the plunger
very slowly
Be very careful not to feed them too much in one go...literally one drop at a time because rabbits aspirate fluid into their lungs very easily. Apparently if you suspect one has aspirated fluid, you can sometimes save it by holding it between the palms of your hands above your head, and then rapidly swinging it towards your knees.
Keep them warm, but give them enough room to be able to move away from a heat source.
Hope this helps