132 BOARD OF AGRICULTURE. 



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of increasirjg the numerator of the fraction. Before taking up the 

 digestibility of each constituent of fodder material, we will examine 

 what is meant by mean coefficient of digestibility. E. Wolff found 

 by experiment that there was a relation between the composition of 

 fodder and the quantit}' of proximate nutritive principles which were 

 digested. This relation maj' be put in the form. of a convenient for- 

 mula which ma}' serve as an indication of the value of a fodder. 

 The formula, though reliable enough, must be used with reserve, as 

 the alimentation of stock is surrounded by so many difficulties and 

 the nature of the digestive and assimilative process so complex that 

 one must be guided b}- practice as well as theory. Experience in 

 the manipulation of fodder and the feeding of stock is verj' neces- 

 sarj' to make the formula as valuable as it may be. The mean 

 coefficient of digestibility according to Wolff, is equal to the quotient 

 of the sum of the albuminoids, extractive carbohydrates and fat, by 

 the total amount of organi^ substance of the fodder. 



Taking examples of various fodders of average composition we 

 have the following mean coefficients of digestibilit}' : 



Hay, about G2 



Aftermath 70 



Clover ha}' 57 



Luzerne hay 56 



Sainfoin 60 



Giving a coefficient of about .60 for the common varieties of hay. 



For the various straws, we have a coefficient of about .40, as can 

 be seen from the following table : 



Wheat straw 39 



Rye straw 37 



Barleystraw 43 



Oat straw 49 



Bean straw 52 



Digestibility of Albuminoids. The digestibility of the albuminoids 

 in the various kinds of fodder varies greatly. In the same kind of 

 'fodder its variations are also very great, being influenced by its con- 

 dition and state of preservation. Tlie albuminoids found in haj' 

 and clover hay may vary in digestibility from 35 per cent, to 75 per 

 cent. The greater the quantity' of albuminoids in fodder the more 

 completely will the}' be digested. Various mathematical formulas 

 for the determination of the digestibilit}' of the albuminoids have 



