Do they also get daily greens?
Reducing pellets usually means increasing greens. What size are your rabbits? If they are normally under 2lbs, then they may need a not overly-limited diet.
I know the following is long, but I think it will help better explain what your rabbit may need. It's from the HOuse Rabbit Society.
Because of several potential problems associated with pellets, some veterinarians now recommend that pellets be not only rationed, but rationed quite severely. Instead of giving the rabbit all she can eat in a day, a night, or a few hours, we have been considering the following amounts as maximums (Brown 1994):
5-7 lb of body wt. 1/4 cup daily
8-10 lb body wt. 1/2 cup daily
11-15 lb of body wt. 3/4 cup daily
There is evidence that small breeds (under 2 lbs) may require a diet higher in energy and lower in fiber than the larger breeds (Cheeke 1987, 324). Several foster homes have experienced digestive problems in rabbits under 4 lbs who were put on severely restricted diets.
Once pellets have been reduced, it is equally important to make sure that fresh grass hay is available to the rabbit at all times, and that fresh vegetables be given in larger amounts than has previously been recommended (up to 2-4 cups a day). Actually, because of the problems usually associated with the overfeeding of pellets, some rabbits do better if they receive no pellets at all. Instead, they eat several cups of fresh veggies a day and all the grass hay they want. Other rabbits still eat pellets, but receive significantly less than the above amounts, with a corresponding increase in the amount of vegetables offered. These more extreme measures are particularly helpful for overweight rabbits who need to lose weight safely. Treats should be limited to small (1 tsp.) amounts of fresh fruit. Most starches should be avoided, since too much carbohydrate has been associated with enteritis. Oats and barley in small amounts can be digested by rabbits but can, nonetheless, provide more calories than necessary.
In feeding trials in which pelleted feed was reduced to 50% of normal intake and the diet was supplemented with greens, young rabbits maintained normal growth. When the amount of pellets was reduced to below 50% of normal, growth rate declined (Pote et al 1980). These studies indicate that even young, unaltered rabbits do well on a reduced pellet diet. Since most of our house rabbits need to lose weight rather than gain, reducing pellets below 50% should not affect spayed or neutered adults adversely.
