APPENDIX 355 



be made. In the case of roots and tubers, grains 

 and industrial by-products, use is made of the 

 number expressing the " value." If, for example, 

 the starch equivalent of rape cake is wanted, and 

 the analysis is 36-5 % crude protein, 8 % fat, 

 25-8 % nitrogen-free extract, and 11-5 % crude 

 fibre, and the digestibility coefficients for the 

 digestible substances being, according to Table II, 

 29-6 % crude protein, 6-3 % fat, 19-6 % nitrogen- 

 free extract, and 0-9 % crude fibre. As, accord- 

 ing to Table I, there are 4-4 parts of amides in 33-1 

 parts crude protein, there will be 4-8 % amides in the 

 36*5 % crude protein in the rape cake. The 4-8 % 

 amides are to be regarded as perfectly digestible, 

 and if they are deducted from the 29-6 % digestible 

 crude protein which the cake contains, there is 

 left 24-8 % digestible proteins. 



24*8 % digestible proteins x 0*94 = 23-3 % starch equivalent 



6-3 „ „ fat x 2-41 = 15-2 „ „ „ 

 2C5 „ „ nitrogen-free ex- 

 tract + crude fibre x roo = 20*5 „ „ „ 



Total . . 59/0 % starch equivalent 



If the nutrients in the rape cake were of full 

 value, the sum obtained above would represent 

 the starch equivalent ; but the value of rape cake, 

 according to Table I, is only 95 %, so 5 % has to 

 be deducted, which leaves the starch equivalent 

 of rape cake at 56-0 %. When dealing with the 



