CATTLE FEEDING. I33 



been proposed ; thej* give us a coefficient of digestibility upon which 

 we must not too much rely, as the variations are very great, and in 

 all cases considerable latitude should be allowed for inaccuracy. 

 One of the simplest of these formulas, thougii not as accurate as 

 some others, is the one proposed by Henneberg : 



E + Z 

 Digestibility of albuminoids = A -f- C- In which E = extractive 



carbohydrates — / = fats — C == total carbohydrates — A = 

 albuminoids. 



DkjestibiUttj of Fats. This constituent also is subject to great 

 variations when we investigate its rate of digestibilit}'. One reason 

 of these variations is undoubtedly due to the fact that the waxy and 

 resinous substances which are generall}' put down in the analyses 

 with true fats are not digestible to any extent. 



The digestibilit}' of the fiitty substance in 3'oung plants is gen- 

 erally gi-eater than that of older plants. The fat found in clover 

 ha}' and the stems of leguminous plants has for its coefficient of 

 digestibility from 40 to 60 per cent., while that of the fatty substance 

 found iu hay and the cereal straws varies from 30 to 45 per cent. 



Digestibility of Carbohydrates. Crude or woody fibre is digested 

 by our domestic animals to a greater or less extent ; the amount 

 digested varies greatly with the different kinds of fodder, being from 

 25 to 70 per cent, of the total quantity. Fibrous and coarse food 

 can be more completely" utilized by the ruminants than by the other 

 animals, as they digest crude fibre more readily. The pig, for 

 instance, seems only to utilize cellulose in its most tender and deli- 

 cate forms, as found in 3'Oung plants and roots. The crude fibre 

 digested b}' animals is cellulose and not lignin. The cellulose of 

 grains and concentrated foods are digested about equall}' b}' our 

 domestic animals. Experiments by Henneberg and Stohmanu upon 

 the digestibility of fibre b}' the ruminants gave the following results : 



Straw of oats 55 per cent. , digested. 



Straw of wheat 52 " " 



Straw of beans 36 " " 



Hay 39 



Clover Hay 60 



Although a part of this insoluble crude fibre is digested, we may 

 be surprised to find that some of the more soluble carbohydrates, 



a 41 



