Basic Herbivore Nutrition

Courtesy of Oxbow Pet Products

Before buying for your next bag of rabbit or guinea pig food, it is important to understand their basic digestion. Rabbits are strict herbivores. This means they need a diet of only plant materials. The digestive system of rabbits (and guinea pigs) contains a large organ known as the cecum. The cecum is a bacteria factory with the full-time job of digesting fiber. So grass hay (such as Timothy, Orchard, Oat or Brome) is an excellent, very high fiber, low calorie, low protein food which keeps the cecum functioning properly. Wild rabbits constantly graze and digest grass throughout the day to keep the cecum full.

Rabbits and guinea pigs have small stomachs, so food quickly enters the intestine which is very efficient at digestion.  Fat, sugar, and starch are quickly converted into energy, leading to obesity. Most of a rabbit's digestive tract is designed to rely on bacteria to ferment fibrous grasses and NOT sugar and starch found in fruits and some vegetables. So, feeds containing a lot of fruit and starch can lead to problems like bloat, enteritis, gastrointestinal stasis, and a number of other health complications.

To keep this type of digestive tract functioning properly, rabbits and guinea pigs need to be fed a diet made from hay. Most pet stores offer both alfalfa-based and timothy hay-based pellets. An excellent quality alfalfa-based pellet, like Oxbow's Bunny Basics 15/23 or Cavy Performance, is ideal for immature rabbits and guinea pigs because it contains optimal protein, calcium and energy for growth while maintaining very high fiber (23%) for digestive health.  Mature animals need fewer calories, so a timothy hay-based pellet should be introduced as the animal matures. Quality timothy hay-based pellets, like Oxbow's Bunny Basics/T or Cavy Cuisine, are high in fiber (25% or more), and contain less protein and calcium than alfalfa-based pellets. Pellets that are lower than 20% fiber tend to be very high in starch based-calories, and will not maintain proper digestive health and weight.

(Growth formulas should be 15-18% protein and 18-23% fiber. Adult formulas should contain less than 15% protein and more than 23% fiber.  All feeds should be fortified with stabilized vitamins and have a calcium-to-phosphorus ratio of 2:1.  Avoid mixes containing seeds, nuts, and fruit.  Look for these numbers and features in the Nutritional Analysis section of the label.)

References:

1. Cheeke, PR.  1987.  Rabbit feeding and nutrition. Academic Press, Inc., Orlando, Florida, 376p.
2. Davies, RR, and JA Davies.  2003. Rabbit gastrointestinal physiology. Vet Clin North Am Exot Anim Pract 6(1):139-153.
3. de Blas, C, and Wiseman, J.  1998.  The nutrition of the rabbit, C de Blas and J Wiseman (eds.).  CABI Publishing, New York, New York, 344p.
4. Irlbeck, NA.  2001.  Feeding the rabbit (Oryctolagus cuniculus) gastrointestinal tract. J Anim Sci 79(E Suppl):343-346.
5. Jenkins, JR.  1999. Feeding recommendations for the house rabbit. Vet Clin North Am Exot Anim Pract 2(1):143-151.