90 SCIENTIFIC FEEDING OF ANIMALS 



value." In order to express this in figures, the full- 

 value feeding-stuffs can be called 100 and the less 

 valuable ones receive a number below 100 depending 

 upon their value. When in Table I of the Appendix 

 it is seen, for example, that the value of barley straw 

 is 46, it means that 100 gr. of the digested material 

 of the straw when added to a maintenance ration 

 only cause an increase of fat equal to that which 

 46 gr. of the same nutrients in pure, finely divided 

 form would give. Substances which depress the 

 action of the other foods are marked with a - sign, 

 e.g. sawdust from pinewood has a value of - 22. 

 This means that the 7-8 gr. of nitrogen-free extract 

 and the 6-9 gr. of crude fibre, in all 14-7 gr. nitro- 

 gen-free extract, which are digested from 100 gr. 

 of pine sawdust, not only have no nutritive value, 

 but reduce the action of the other food by 22% of 

 the amount which would be obtained if the nutrients 

 of the sawdust were of full value. 



In the 100 gr. sawdust 14-7 gr. are digestible, and 

 22% of this is 3-2 gr., so the addition of the saw- 

 dust acts as though 3-2 gr. of starch had been taken 

 from the food instead of sawdust being added. 



By means of this " quantitative number " exact 

 expression is given to the action of the digestible 

 materials contained in each food-stuff. Further 

 investigations have shown that the coarsely ground 

 cereal grains without husks, and feeding-meals 

 free from chaff or bran, are of full value. The 



