610 THE HOME, FARM AND BUSINESS CYCLOPAEDIA. 



The influence of high manuring is naturally to increase the luxuriance 

 of a crop ; a luxuriant crop will always contain more water than one in 

 less active growth. Very large mangels often contain only 6 per cent, of 

 dry matter, while in quite small roots the proportion may be as high as 15 

 per cent. Luxuriance also retards maturity. A heavily manured mangel 

 will contain, at the same date, a much smaller proportion of sugar than a 

 similar mangel grown on poor soil. The result of high manuring is thus 

 not only to increase the bulk of the crop, but also generally to diminish 

 the proportion of carbo-hydrate^., and increase the nitrogen, ash constitu- 

 ents, and water. In highly manured crops a smaller proportion of the 

 nitrogen will exist as albuminoids than in crops less heavily manured and 

 more mature. 



An important element in the character of a food is the proportion be- 

 tween its nitrogenous and non-nitrogenous constituents, these two classes 

 of ingredients performing to a considerable extent distinct functions in 

 the body. To find this proportion it is usual to calculate the fat into its 

 equivalent in starch (generally done by multiplying the fat by 244), and 

 add the product to the other carbo-hydrates of the food ; the relation of the 

 albuminoids to the total non-nitrogenous constituents reckoned as carbo- 

 hydrates is then easily found. The relation in question is commonly 

 known as the " nutritive relation " of the food (Nahrstoffverhaltniss), but 

 is better described as the " albuminoid ratio." Thus the composition of 

 wheat grain in the table shows an "albuminoid ratio" of 1:66, and the 

 composition of decorticated cotton cake an albuminoid ratio of 1:15. 

 Figures so calculated are, however, only approximate, as we ought clearly 

 only to take account of the constituent actually digested by the animal. 

 A little consideration will show that it is impossible to affix a definite 

 feeding value to any food, as its practical effect must depend in great 

 measure on the conditions under which it is employed ; more especially 

 on the kind of animal consuming it, and the general character of the diet 

 of which it forms a part. Thus, the value of a bulky food, as hay or 

 straw, is far greater when given to a ruminant animal, than when con- 

 sumed by a horse or pig. Concentrated, easily digestible foods, as corn 

 and oilcake, have clearly a value above their composition when added to 

 a poor and bulky food, as straw chaff, or to a watery food like turnips, 

 because they are the means of raising the diet to a point at which the 

 animal will thrive. On the other hand, roots and green fodder, even 

 when watery and poor in composition, may have a considerable effect 

 when added in moderate proportion to dry food. The highest value 

 is, in short, only obtained from food when it is skilfully employed. 



