FOOD NUTRIENTS 



47 



ducted, the solid excrements are collected, weighed 

 and analyzed by the same chemical methods applied 

 previously to the food. By this plan the amount 

 of each constituent of the food which has passed 

 through the animal unabsorbed is determined. It 

 is a simple matter now to subtract this quantity 

 from the amount found to have been present in the 

 food originally and to obtain the difference, which 

 is the amount digested and absorbed. 



First Step Is to Obtain Composition. Chemists 

 have analyzed all the important feeding stuffs, 

 Slight variation is noted, which is due largely to 

 difference of variety, soil, climate, season, fertiliza- 

 tion and culture. Based on averages, the resulting 

 figures of composition are sufficiently accurate for 

 all purposes of ration building. In the table follow- 

 ing a few common feeding stuffs are included for 

 assistance in determining the real nutritive value of 

 each constituent. 



COMPOSITION OF SOME COMMON FEEDING STUFFS 



