Rabbit Digestibility

Different foods, and the different constituents of foods, vary in their digestibility. Thus in order to arrive at the true valueof any particular food it is necessary to know not only thechemical composition of that food, but the amount of eachconstituent which is digested by the animal.

Different strains, and different rabbits within a strain do notvary greatly in their powers of digestion of the same food atequivalent ages, thus once the digestibility coefficients (thatis the percentage of the amount of food consumed which isdigested) of a food are known, they can be applied to thatlhod for all mature rabbits.

There are a number of factors which affect the digestibilityof any feeding stuff, probably the most important is the amountof fibre it contains. As the proportion of this constituentrises, so the total digestibility falls. Furthermore, as theproportion of fibre rises so the individual digestibilities of thevarious constituents of the food fall. The reason for this isthat the fibre tends to protect the more digestible constituentsfrom the digestive juices.

The depression of the total digestibility of a food by increasingfibre content, is fairly constant. When the fibre content isabout 35% of the dry matter of the food, then the totaldigestibility of the organic matter of the food (i.e. excludingsuch materials as minerals) is about 40%. This figure may riseto as much as go% when the fibre contests is eliminated The ability to digest fibre increases with the age of the rabbit.Young animals can digest this material to a very limited extent,and consequently, rations for them should be lost in fibre.The speed with which food passes through the digestivetract has some influence on total digestibility, as has also theamount of food fed. Thus a rabbit which is excessivelyhungry and in poor condition, and a rabbit which is fat andreceiving an excessive amount of food will not digest nor utilise the food to the maximum efficiency.