Rabbit Diet

Rabbits are obligate herbivores designed to consume large amounts of plant material which is high in indigestible (lignified) fibre. They should be fed on good hay, fresh grass, wild plants, herbs, dried grass, good grass or hay based pellets supplemented with vegetables, a little fruit as a treat and willow, fruit or hazel twigs to strip.
Their wild diet consists of grasses and wild plants supplemented with roots and bark when food is scarce. Their teeth grow continuously and need the constant chewing action involved in eating 100 small meals a day, and the abrasive action of the mineral rich fibre against their teeth, to keep them ground down to a suitable length.
The rabbit's digestive system depends on the indigestible fibre in the diet to keep keep food moving through the gut at the right speed. Too fast and the rabbit cannot digest food, too slow and the pH of the gut starts to favour disease causing bacteria instead of the friendly bacteria that help the rabbit break down digestible fibre, protein and carbohydrate.
The length of fibre is also important, finely powdered plant material cannot be used as indigestible fibre. The minimum length of fibre used in rabbit pellets should be 2.5mm. Unfortunately, manufacturers of rabbit feeds are only required to list total fibre in the declared analysis. There is no way of really knowing how much of that is digestible and how much indigestible. Digestible fibre is used for energy in much the same way as carbohydrate. There is also no minimum length of fibre required, so if the fibre used is too short then the total fibre quoted can again be misleading.
The best rabbit food I have come across is the German Bunny range of diets available in the UK from Zooplus. All of them are high fibre and other than the addition of some wheatgerm and oatgerm they are grain free. In fact they are almost entirely made up of a range of herbs and grasses. The unique shape of the Bunny pellets encourage good wear on the teeth and allows the inclusion of long fibre in the pellets themselves that is essential for the rabbit gut. Bunny Green Dream Young is 15% protein and 20% fibre; Bunny Green Dream Staple is higher in fibre at 21% and lower in protein at 13% but still with the same healthy hay, grass and herb ingredients. There is also a herbal version, Bunny Green Dream Herbal with 20% fibre and 12.5% protein.
Check the analysis of many of the rabbit foods on the market and although the Small Animal Veterinary Association recommends a diet high in fibre with a lower level of protein, many rabbit foods do not have enough fibre or have too much protein in relationship to fibre.
Rabbits are selective feeders and may refuse to eat certain ingredients in a mix leading to dietary imbalance and health problems. The coloured biscuits, grains and pulses in rabbit mixes would not normally form a part of the natural rabbit diet and manufacturers compensate for this by adding extra calcium and fibre to the pellets in the mix to balance the excess phosphorous in the grains and the lack of fibre in those other ingredients.
A rabbit which eats only the biscuits and flakes from a mix runs the risk of calcium deficiency and slow transit time through the gut (leading to dysbiosis). A rabbit eating only the balancer pellets from a mix would be consuming excess calcium which might cause problems if not excreted. Fortunately rabbits have the ability to excrete excess calcium in their urine, leaving a white 'tide mark'. If the levels are too high then the rabbit may develop gravel in the urine or calculi (stones)