When choosing a diet for a house rabbit, remember that as an herbivore (plant eater), a rabbit constantly needs food moving through its digestive tract. The specific diet you choose for your rabbit will depend on several factors, including age and weight of the rabbit, environmental conditions, and purpose of the animal.
Rabbits are concentrate selectors, so they naturally pick and choose foods higher in energy density. Providing a pelleted rabbit food helps ensure that your animal is getting all the nutrition it needs in each bite of food. A pelleted diet is formulated to contain the nutrients the animal needs from a variety of feed ingredients, but primarily hay. These ingredients are mixed together thoroughly and then compacted and produced to be consistent in size and nutrient composition. This approach eliminates the ability of the rabbit to sort the food. There are pelleted diets designed for different life stages of rabbits. A pellet with a basis of primarily alfalfa hay provides added protein and calcium for younger, growing rabbits and those that are pregnant and nursing. A pellet with a basis of primarily grass hay (generally, timothy) is better for an adult animal that is a pet.
Seed mix diets are not ideal for everyday feeding because the rabbit may pick and choose items based on its taste preferences and may not choose the most healthful seeds. Studies have shown that rabbits tend to choose the parts of this diet that tastes best to them. This behavior tends to result in rabbits consuming a diet too high in fat and too low in some vitamins and minerals.
Some rabbit owners choose to feed an entirely home-prepared diet. If you choose this option, do so with careful consideration. Feed your rabbit a variety of nutrient-dense vegetables with a limited amount of fruit. Vegetables such as dandelion greens, Brussels sprouts, parsley, and other dark-colored vegetables are ideal. Additional ingredients you may use in a home-prepared rabbit food include cereal grains, such as wheat and oats; soybean meal; or roots, such as sweet potatoes. Avoid or limit carrots and iceberg lettuce because these vegetables contain fewer nutrients. A rabbit on a home-prepared diet may need supplemental vitamins and minerals in the form of a salt lick or trace mineral supplement. Discuss the use of home-prepared diet formulations with your veterinarian before beginning to feed one to your rabbit.
Younger rabbits (less than six months old) require increased nutrients for growth and development. Provide growing rabbits unlimited amounts of alfalfa hay, a legume containing higher amounts of calcium and protein useful for growth and development.
Offer a pelleted feed starting at about three weeks of age, providing unlimited amounts of a high-quality alfalfa-based pellet until the rabbit reaches six months of age. A diet with at least 15 percent crude protein and 14 percent crude fiber meets the needs of a growing rabbit. Avoid diets with large excesses of dietary protein (greater than 20 percent) because these diets may result in poor air quality in the area where your rabbits are housed. Rabbits excrete excess protein as urea in the urine. Due to rabbits' high water intake, they excrete large quantities of urine. These two factors combined can result in higher humidity or moisture and the breakdown of urea to ammonia vapors.
Energy levels in a rabbit diet for growth should be between 2,400 and 2,800 kilocalories per kilogram. Excess calories in the diet can actually decrease the food and energy intake of rabbits and predispose them to other health issues. Generally, diets with higher energy density have lower fiber, which is essential for gastrointestinal tract health in rabbits. Low fiber results in constipation or enteritis (diarrhea). A diet containing high energy grains, such as corn, may be unsuitable for a growing rabbit because it may increase the risk of enteritis due to the high carbohydrate content. You should feed based on the ideal body weight of your animal to prevent obesity.
Calcium and phosphorus are important minerals to consider when planning a young rabbit’s diet. The ingredients used in commercial rabbit feeds should provide ample amounts of these minerals. Calcium is provided from alfalfa and alfalfa meal found in the pelleted diet. Phosphorus is generally provided by grain by-products, such as wheat bran or wheat middlings. You need not provide additional calcium or phosphorus in the diet. In addition, a high-quality diet provides all the needed vitamins and trace minerals so that a salt or trace mineral lick is not needed.
The highest nutrient demands are for rabbits that are pregnant or lactating (producing milk). These animals have higher protein requirements and should be fed a diet with at least 18 percent protein. This protein can be provided by alfalfa meal in the pelleted diet and through free access to alfalfa hay. You may include soybean meal in the diet as well to provide additional protein.
Pregnant and nursing rabbits also have the highest energy needs. Nursing or lactation peaks between ten and 21 days after giving birth, and this is when the rabbit has the highest energy requirement. Digestible energy in a diet for pregnant and nursing rabbits should be between 2,500 and 2,900 kilocalories per kilogram. Often at peak lactation, rabbits are in a negative energy balance. This means that they require more energy for milk production than they get from their diet and must use body tissues to meet energy needs. Try to minimize this energy deficit as much as possible. Rabbits should be in good body condition to slightly overweight when bred to ensure a successful mating. However, obesity during pregnancy can result in smaller litter sizes and death of kits at birth. Increased death rates are due to both large size of kits at birth and accumulation of fat deposits in the doe’s abdomen increasing the risk of birthing difficulties such as dystocia.
You can use added fat (about 3 percent) to increase energy content of the diet without increasing carbohydrate levels. Pregnant and lactating rabbits can tolerate more carbohydrates in the diet than young, growing rabbits or adults at maintenance.
Proper levels of calcium and phosphorus should be provided in the diet from alfalfa hay and other ingredients. The rabbit has higher needs for calcium and phosphorus to allow for skeletal development of the fetuses and adequate levels in the milk. Too much vitamin A can result in reproductive problems such as fluid on the brain (hydrocephalus), low survival rates, and low conception rates. There is no need to supplement additional vitamin A to an alfalfa-based diet because alfalfa contains adequate amounts of beta-carotene, the precursor to vitamin A.
Allow pregnant and nursing animals free access to both alfalfa hay and high-quality alfalfa-based pellets to meet nutrient needs.
For an adult rabbit, an alfalfa-based diet has more calcium and protein than what is required for maintenance. Many commercially available rabbit foods are designed for production animals. These diets have too much protein and calories for an adult companion rabbit. Feeding these diets can result in a rabbit that is overweight, has soft stools, or may have urine sludge or urinary tract health issues due to excess calcium in the diet. For an adult rabbit at maintenance, choose a grass hay-based diet with no more than 16 percent protein and no less than 20 percent crude fiber.
Avoid a diet that has too much sugar or starch from ingredients such as corn or seeds. Adult rabbits do not tolerate high levels of carbohydrates and have lower energy requirements. Digestible energy concentrations of about 2,200 kilocalories per kilogram of diet meet the energy needs of an adult rabbit. High-energy or high-starch diets are most likely to cause gastrointestinal upset and lead to diarrhea, poor food intakes, obesity, and other health concerns. Feed your rabbit its pelleted diet based on the label guidelines, and monitor closely for obesity. Obesity can impair the animal’s ability to groom itself, cause organ damage, and interfere with proper digestion. An animal at a healthful weight will have a longer life span.
As with younger rabbits, the calcium and phosphorus contents of the adult rabbit diet are critical. Adult rabbits require lower levels of calcium and phosphorus than at other life stages. They are able to absorb adequate amounts from the diet, and any excess consumed is filtered out by the kidneys and excreted in the urine. You may notice a white substance in your rabbit’s urine; this is excess calcium. If calcium levels are too high for too long, the rabbit may develop kidney damage and urinary stones. Grass hay is lower in calcium than alfalfa, making it preferable for a companion rabbit diet.
Offering unlimited access to grass hay is an essential component to feeding your rabbit. Grass hay is not only vital to the digestive tract, but it helps prevent obesity, diarrhea, dental disease, and boredom. Such grass types include but are not limited to timothy, orchard, brome, and oat hays.
Choosing a diet that is designed for the life stage of your rabbit is important. Alfalfa-based diets are appropriate for young rabbits and pregnant or nursing rabbits; grass-based diets are better suited for adult rabbits. Growing, pregnant, and nursing rabbits can be fed unlimited pellets, but adult rabbits should be limited to the amount of food suggested on the label. All rabbits should have access to hay at all times—alfalfa for those with highest nutrient demands and grass for adults.
Lisa Karr-Lilienthal, PhD, University of Nebraska-Lincoln