What a rabbit wants to eat and what a rabbit should eat are two different things. Since a rabbit's digestive system is sensitive, it is important to know what your rabbit needs to consume.
What to Feed Rabbits
Fiber is vital to the normal function of the digestive system in rabbits. Fresh grass hay and vegetables should make up the bulk of the diet for house rabbits. Feeding a diet consisting mainly of pellets may result in obesity and increase the likelihood of digestive problems for your pet rabbit.
While there is some fiber in pellets, it is finely ground and does not appear to stimulate intestinal function as well as the fiber found in grass hays. The addition of some pellets does add some balance to the diet, however, if your rabbit is a picky eater.
Anything other than hay, vegetables, and pellets is considered a treat and should be feed in strict moderation. The number of pellets should be restricted, especially in overweight rabbits, but any reduction in pellets should be made up with a variety of fresh vegetables and unlimited access to hay.
Feeding Rabbits Hay
Hay (specifically grass hays, such as timothy or oat hay) should be available at all times to your rabbit. Some rabbits may not eat much hay at first, but by adding fresh hay a couple of times a day and reducing the number of pellets you offer, your rabbit will likely become hungry enough to eat the hay.
Vegetables for Rabbits
Vegetables should make up a large portion of your rabbit's diet. A variety must be fed daily to ensure a balanced diet. Suggested vegetables to feed include carrots, carrot tops, parsley, broccoli, collard greens, mustard greens, dandelion greens, turnip greens, endive, romaine lettuce, kale, and spinach. However, kale, spinach, and mustard greens are high in oxalates, so their feeding should be limited. Beans, cauliflower, cabbage, and potatoes may cause problems and should be avoided. Iceberg lettuce has almost no nutritional value and can cause diarrhea, so it should be avoided as well.
Vegetables should be introduced to bunnies around 12 weeks of age, in small quantities, and one at a time. As more vegetables are added, watch for diarrhea and discontinue the most recently added vegetable if this occurs.
Feeding Rabbit Pellets
Pellets are basically designed for commercial rabbit production and are quite high in calories. As a result, house rabbits fed unlimited pellets may end up with obesity and related health problems, as well as an excess of other nutrients. Pellets do have a place in rabbit nutrition, as they are rich and balanced in nutrients. However, experts recommend restricting the number of pellets fed and instead feed more fresh vegetables and grass hays.
Choose a fresh, good quality pellet. The House Rabbit Society recommends a minimum of 20-25 percent fiber, around 14 percent protein (no animal protein), and less than 1 percent calcium for most house rabbits (spayed/neutered). For adults, the amount should be carefully regulated depending on the size, by weight, of the rabbit.
As a rule, give about 1/4 cup of pellets to rabbits 5 to 7 lbs., 1/2 cup for 8 to 10 lb. rabbits, and 3/4 cup for 11 to 15 lb. rabbits. Baby rabbits can be fed pellets free choice (available at all times) and then the amount can be decreased to 1/2 cup per 6 lb. of body weight by around 6 months of age.
Treats for Rabbits
The House Rabbit Society recommends that 6-pound mature adult rabbits (1 to 5 years) be feed 2 tablespoons of fresh fruit daily as a treat. Treats sold in pet stores marketed for rabbits are generally unnecessary, and in some cases could cause digestive problems due to their high carbohydrate or sugar content. Also, as an alternative to food treats, consider offering twigs from apple or willow trees (pesticide-free only) or other rabbit safe woods.