The level of protein in the diet is determined by its percentage of total diet, its bio-availability and its amino acid profile. Amino acids are the building blocks the body needs to create and repair tissue. When the body has more than it needs for building and repair, the excess is used as an energy source.
Young, pregnant and lactating animals require higher levels in the diet. Animals with kidney problems are usually recommended to stick to a low protein diet. Excess protein can cause sticky bottom in rabbits and soft droppings in guinea pigs and chinchillas. The relationship with fibre in the diet is also important for optimum health.
Although chinchillas in the wild sometimes eat small insects, rabbits and guinea pigs are obligate herbivores which means they obtain their protein requirement from plant material, mainly grasses, roots and wild plants. In the wild the protein and fibre levels in the diet of these animals would fluctuate according to the seasons. Breeding normally takes place after a period where the protein levels in the wild diet are low and the fibre levels high, with mating occurring as the protein levels increase and the fibre levels drop. Young green leaf is higher in protein and lower in fibre than older, stalky material.
Many commercial diets contain grains and pulses which have a different nutritional profile to grass and other forage. Although these can be used to control the protein level of a feed, up or down, consideration must also be given to to the low levels of indigestible fibre in these foods and their high phosphorous to calcium ratio.
The level of protein in the diet is determined by its percentage of total diet, its bio-availability and its amino acid profile.
Foods with high levels include pulses such as peas & beans at 26%, dried grass at 19% and alfalfa or lucerne at 22%. Grains such as oats, barley, wheat and maize contain 9% – 12%. The protein level of grains is calculated using the whole grain which contains fibre in the husk. Wheatfeed which is used to make the biscuits or extrusions found in many mixes contains 17%.
Guinea pigs have a higher protein requirement at 17% than rabbits which require 13% for maintenance or between 16% and 18% if they are growing or being used for breeding. Guinea pigs also require 30% – 35% more arginine than rabbits for optimum growth.