CHEMISTRY OF FOODS AND FEEDING. 



1177 



it contains will be wasted. Failure to appreciate this fact has 

 in many cases brought discredit on chemical analysis as a means 

 of determining the feeding value of foods. A comparatively 

 poor food, if all digested, may be of more real value than a 

 very rich one, of which a large portion is indigestible. 



No table of the digestibility of food could be prepared which 

 would be absolutely and always correct. The same article will 

 differ in digestibility according to soil, season, and manner of 

 curing. Different classes of animals have different powers of 

 digestion, and no two animals, even of the same kind, are ex- 

 actly alike in this respect. Tables of digestibility, therefore, 

 can only be approximate, and must be used as guides, not as 

 absolute rules. 



The following table gives the number of pounds of digesti- 

 ble constituents in a ton of various foods, as determined by 

 taking the average of a large number of experiments with cattle 

 and sheep. It will be noticed that in many respects it differs 

 very materially from the preceding table : 



Horses have not as much power in digesting coarse food as 

 cattle and sheep, but for concentrated food their digestive pow- 

 ers are about equal. Swine have great digestive powers on con- 

 centrated foods, and can digest well a reasonable amount of 

 green foods, but have not the stomach-room to take and digest 

 large quantities of coarse food, like cattle and sheep. 



The degree of maturity of some crops has great influence on 

 their digestibility. Young grass is much more digestible than 



