I would not give them that, their digestive systems can not handle cows milk. You may be able to give goats milk or kitten milk replacer.

All I can really pass on is this info from the House Rabbit Society.

In the rare situation that you have an orphaned domestic bunny, such as when a domestic rabbit mom is sick or refuses to care for her young, you will need to feed the babies. Overfeeding is a leading cause of death in these youngsters which results in fatal intestinal disease.  

Use Meyenberg Regular Goat milk (found at Safeway in the milk section or Whole Foods) or KMR KITTEN powder formula + follow directions on the can. (KMR better for domestics). It may be easiest to start with a 3 cc/ml syringe or an eyedropper. Some use pet nurser nipples on the end of a luer lock syringe, or a teat cannula on the end of a syringe. Feed only with the bunny sitting UPRIGHT, and point syringe down towards bottom or side of mouth, so if too much comes out, the baby does not aspirate! For those who are slow to learn nursing, SC fluids may be necessary to prevent electrolyte imbalance or dehydration (check with a vet on this only!!). Domestic buns with closed eyes should be fed 2 x a day, and the number of feedings gradually decreased until they are weaned. If their eyes are still closed, you need to stimulate their bottoms with a warm moist towel after feedings to help them to pee. (Domestics are weaned about 6 weeks; wild bunnies are weaned about 3-4 weeks for cottontails and 9 weeks for jacks). Bloat is commonly associated with too frequent feedings and too much at one time. Full article: http://www.rabbit.org/faq/sections/orphan.html

Is the mother lactating?  Make sure she is been feed higher protein feed. This is HRS advice on assisted feeding also ( I know you’ve tried this)  I would keep trying to get onto another vet and or rabbit rescue or wild life rehabilitators for some more advice.

If the babies have not been fed, they will have sunken tummies, their skin will be wrinkled from dehydration and they will be weak (their response to being handled will be weak or non-existent, although they will hopefully be breathing.) Scattered babies are more likely not to have been fed, so make sure that they are warm first.

If the babies are weak or dehydrated, veterinary intervention is advised. Placing a drop of honey or fruit jam into their mouths sometimes helps elevate their blood sugar level until veterinary help and/or mother’s milk is available.

At this point, examine the mother for signs of lactation. By gently holding the mother upright, or gently turning her upside down in a lap, the nipples can be examined. They should feel slightly swollen and it is likely that the mother pulled a great deal of fur from her chest and stomach to not only make her nest, but also to better expose the teats for the babies.

Slight pressure in a milking motion should release either small amount of milk or clear fluid. If the mother is lactating, return her to the babies and allow her to calm down and become familiar with her new nest. Examine the babies the next day to make sure that they are being fed.

If the mother is definitely not lactating or has not attempted to pull fur or make a nest, etc., take the mother to a qualified rabbit-experienced veterinarian immediately. The veterinarian will probably give the mother a small dose of oxytocin, a drug that will stimulate the milk glands. She should nurse within the next 24 hours.

 

If you feel it is necessary to examine the babies every day to verify that they have been fed, pet the mother rabbit first, to help cover human scents, and avoid wearing heavy perfumes when handling the babies. It is best to handle the babies as little as possible until they are old enough to leave the nest box on their own.

If your concerns begin on the day of the birth, wait a day before attempting to do anything. Some mother rabbits do not feed their babies until the evening of the first day or early on the second day.

If it has been close to two days and you are positive that the babies have not been fed, a veterinarian must be seen immediately. Oxytocin will not produce results if you wait more than forty-eight hours after the birth.

While waiting for a veterinary appointment, try allowing the babies to nurse, as suckling sometimes stimulates the milk glands. If that happens, monitoring the babies’ growth is the only thing that needs to be done. Mother rabbits stand upright while nursing and the babies lie upside down beneath her. Hold the rabbits in this natural position. http://www.rabbit.org/care/babies.h…by_Rabbits 

What Jersey posted is pretty much the extent of what we can offer. The majority of us do not have any experience with baby bunnies and only know the textbook basics (keep them warm, KMR, etc…) I would urge you to continue your search for a vet (or possibly rescue group) that will be able to offer further guidance. Please update us on how the babies are doing.