The majority of a rabbit's diet should be hay. Free feed of timothy hay is very important to a rabbit's health. It contains necessary nutrients and roughage to help control hairballs. Alfalfa hay may be given occasionally as a treat but timothy hay should be made available at all times (see below for info on timothy hay as the litter box material). Alfalfa hay is very high in calories, protein, and calcium and can lead to obesity and/or kidney problems.
Carrots, carrot tops, broccoli, apple slices (no seeds as they are toxic!), banana slices, parsley, watercress, mint, cilantro, frisee, radish tops, alfalfa sprouts, kale (occasionally), bok choy, celery, chicory, collard greens, dandelion, green leaf and romaine lettuce (no head lettuce!!), pea pods (flat), tiny amounts of unsweetened cereals, and bits of bread are some of the additional food items that are acceptable for a rabbit to eat. Fruit should be limited to one tablespoon per day.
One thing to avoid is sugar; as it increases the bad bacteria in their intestines and can cause disease resulting in diarrhea and loss of appetite. Also avoid spinach, cabbage, cauliflower, mustard, raw beans, potato peals, rhubarb, or any spoiled food.
Fresh water should be available at all times. Change bowls and/or bottles at least once a day even if they are not totally empty! Heavy ceramic food and water bowls are recommended because they cannot be overturned. Wash bowls and bottles frequently to remove any buildup of scum.
Use commercially produced pellets purchased from a feed or pet store to insure that the quality of the food is consistent. Never purchase over an eight week supply of food at a time or it may spoil and cause the rabbit to stop eating. An adult rabbit will consume about five to ten pounds of food in this time period. Also, once a particular brand of food has been chosen, stick with it. Sudden switching of food can be detrimental to your rabbit's health. If a change in pellets is necessary, gradually change from one type to another by mixing them together until the old food is finished.
Protein: Short haired rabbits should eat pellets containing 16% protein, while Angoras should get 18 to 20%.
There is a controversy about the amount of pellets to feed a rabbit. Our experience is that pellets should be rationed. If your rabbit has a weight problem, restrict the amount of food to 1/4 cup per day (for an 8 pound bun) until his/her weight is normal. Experimentation will be necessary to determine the proper amount to feed.