134 BOARD OF AGRICULTURE. 



called extractive carbohjclrates, are lost in the process of digestion. 

 A sort of balance is however established between the fibre digested 

 and the carl)oh3'drates undigested, so that the amount of extractive 

 carbohydrates found in a fodder represents about the quantity of 

 mixed fibre and extractive carbohydrates which will be digested. 



The amouiit of extractive carbohydrates present in a ration would 

 give us a rough indication of the amount of total carbohydrates an 

 animal could utilize. This method cannot be considered very exact, 

 the amount indicated b}- it being sometimes as much as 20 per cent, 

 too large or too small. 



For young plants in which woody fibre is not present in very large 

 quantities, and in which it is comparatively tender, the method 

 above given seems quite valueless, as the amount of carbohydrates 

 digested is nearh' invariabh' more than the amount of extractive 

 carbohydrates found in the fodder. From experiments by Henne- 

 berg and Stohmann it would seem that the amount of substance in 

 coarse fodder which is soluble in boiling water is about equivalent 

 to the amount of digestible carbohydrates. 



The following table gives the results arrived at : 



!Kinds of fodder. Soluble in boiling water. Digested carbohydrates. Diflference. 



Oat Straw 3.25 3.17 +.08 



Wheat straw 94 1.07 — .13 



Bean sti-aw 5.18 5.34 —.16 



Clover hay 11.24 11.30 —.06 



Hay 6.42 6.36 + .06 



It must be borne in mind that this method can only be used when 

 rough approximations are sufficient. Comparative experiments 

 have shown the results to be far from accurate. The undioested 

 carbohjdrates are generally richer in carbon than the digested part, 

 containing 55 to 56 per cent., while the digested portion onl}' con- 

 tains 44.4 per cent. ; these carbohydrates are probably all converted 

 into sugar during the process of digestion and assimilation. 



Mineral Substances. These are generalh* offered in sufficient 

 quantity to animals in their rations. The salts necessary- to the 

 animal are easil}' taken up, provided they be in a somewhat soluble 

 condition. The addition of phosphate of lime to the rations of 

 growing stock is sometimes very useful. The presence of phos- 

 phoric acid is of utility in nearly all kinds of animal production. 

 Nearly all the alkaline salts of the fodder pass out, 95 to 97 per 



