1911.] Concentrated Feeding-stuffs. 



227 



The method works fairly well in practice so long as only 

 materials of similar character are compared, but is very un- 

 reliable if applied to foods of widely differing character. 



Second Method. — In this method the manure-value per 

 ton of the foodstuff (see Table, p. 225) is first deducted from 

 the price, and the balance then regarded as the nett cost. The 

 subsequent procedure is then similar to that used in the first 

 method, except that only the percentage of digestible oil is 

 multiplied by 2J-, the albuminoids in this case being ranked 

 equal only to the carbohydrates. This is in accordance with 

 the most recent determinations of the relative values of the 

 nutrients to the animal for productive purposes. Other 

 factors which tend to raise the market value of albuminoids 

 bevond this level will be discussed later. 



For the purposes of illustration the case of the linseed cake 

 and decorticated cotton cake compared in Example II. above 

 may be taken. In each case the nett cost per ton is equal to 

 the price per ton, less the manure value per ton; thus : — 



Nett Cost per Ton. 

 Linseed Cake ... £g - £i iSs. yd. — £j is.$d. 

 Decort. Cotton Cake £8 i$s. -£2 16s. $d. = £$ \%s. id. 



The number of food " units " in each case will be — 



Linseed Cake ... (10 x 2\) + 27^ + 26^ — 79. 

 Decort. Cotton Cake (8i x 2^) + 34^ +18 =74. 



The cost per "unit" of the linseed cake will be 



£7 is. 5<^ =I s. qIJ. x \t this rate the nett cost of the cotton 

 79 



cake should not exceed 74 x1s. g\d., or £6 12s. yd. This 

 will represent a market price of (£6 12s. yd. + £2 16s. $d.) 

 or £g gs. per ton. 



This method of assessing the comparative values of food- 

 stuffs can be used with slight modification for the comparison 

 of foods of very different character. In this case the " food- 

 unit " totals by themselves are not a true measure of the 

 relative values of the foods to the animals, since they take 

 no account of the fact that the matter digested from an easily 

 digestible food is utilised in the animal much more efficiently 

 and economically than the matter digested from a more 

 indigestible foodc This difference turns largely upon the 

 amount and character of the crude fibre present in the different 



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