COMPUTING RATIONS BY STARCH VALUES 85 



Thus the 78.7 pounds represent the calculated 

 starch value of 100 pounds of linseed cake, which 

 actually had the same fattening increase as 77 

 pounds of starch. 



Actual Starch Value Below Calculated Starch 

 Value. When put to actual tests the calculated 

 starch values failed to show an increase in produc- 

 tion that the values really indicated them to possess. 

 This is particularly the case with foods containing 

 much fiber. The difference is accounted for in the 

 work occasioned in digesting the foodstuff. Foods 

 like cottonseed meal, linseed meal, corn, etc., possess 

 little fiber, and therefore, the work of mastication 

 and digestion requires only a small part of the nutri- 

 ents contained in them for their necessary but un- 

 productive purposes. Foods like wheat bran, oat 

 straw, hay, etc., on the other hand, require much 

 labor in the digestive processes, and consequently 

 much of their nutriment is used up in this way. 



Kellner has met this difficulty by assigning co- 

 efficients of availability to each feeding stuff based 

 on its calculated and actual starch values. Some of 

 these are given on the next page. 



Considerable variation is here noted. The oil 

 meals, which carry little fiber, are very largely avail- 

 able on the basis of their calculated starch values. 

 Wheat bran has more fiber and its coefficient of 

 availability drops to 77. The more fibrous meadow 

 hay drops to 70, while oat and wheat straw, with 

 much fiber, go down to 61 and 29 respectively. 



Calculating Starch Values on Basis of Availabil- 

 ity. To reduce the calculated starch values to their 



