Fibre is an essential element of the rabbit, guinea pig and chinchilla diet. Plant material contains both digestible and indigestible fibre. The indigestible (or lignified) fibre helps maintain the movement of food through the gut whilst the digestible fibre is broken down by enzymes and bacteria in the gut to provide energy.
The fibre requirement of lactating does and sows is lower than that for those animals on a maintenance diet. Of the crude fibre in the diet 65% -70% should be indigestible to ensure the correct rate of other nutrients passing through the digestive system.
Fibre in the diet tends to protect the more digestible ingredients from the digestive juices so a diet which contains high levels of fibre, for example 30%, is only 48% digestible compared to a diet with 15% fibre which is 69% digestible.
Diets low in fibre cause serious digestive problems in rabbits, guinea pigs and chinchillas. Crude protein should be 80% - 90% of the crude fibre level. High fibre foods include hay at around 30%, alfalfa at 24% and dried grass at 21%. Straw is even higher in fibre but has very little food value.
When balancing dietary fibre, it is important to also consider other factors when comparing sources of fibre, including the level of calcium and its relationship with phosphorous and the protein levels. In legume hays such as clover and alfalfa, these levels are high, whereas in oat straw they would be extremely low. Greener products, such as dried grass, alfalfa and young leaf hay, tend to have higher levels of vitamin C.