I 9 II.] 



Concentrated Feeding-stuffs. 



219 



General Composition of Foods. 



The component parts of all foods, whether home-grown or 

 purchased, may be classed as follows : — 



Feeding Stuff 



Water Dry Matter 

 <■ 



Nitrogenous Non-nitrogenous 

 substances. substances. 



Albuminoids (Proteins) Fats and Oils 

 Amides Soluble Carbohydrates 



Crude Fibre 

 Mineral matter (Ash). 



Commencing from the top, it will be seen that feeding- 

 stuffs are primarily made up of water and dry matter, and 

 that the latter consists of nitrogenous and non-nitrogenous 

 constituents, which, again, may be sub-divided — the nitro- 

 genous into albuminoids and amides, the non-nitrogenous 

 into fats, carbohydrates, fibre, and mineral matter. 



Albuminoids . — The albuminoids (or proteins) form a large 

 and complex class of compounds. They are the true flesh, 

 lean meat or muscle formers, and are sometimes termed the 

 "essential" or "indispensable" food ingredients, because 

 without them life could not be maintained. They contain 

 nitrogen to the extent of about 16 per cent., which, together 

 with part of the carbon, hydrogen, and oxygen, is utilised 

 for the construction and repair of animal tissue; while the 

 rest of their carbon and hydrogen, by combustion in the 

 body, is utilised to maintain the heat of the animal and to 

 supply energy or mechanical force. Beyond this, the albu- 

 minoids, if used in excessive quantity, may contribute to the 

 production of fat, or, at least, may protect the fat stored up 

 in the tissues from consumption. Only a relatively small 

 proportion of the excess can be used in this way, however, 

 and the rest is merely burnt up, and has no more value than 

 an equal amount of carbohydrates, which are much cheaper. 

 Many farmers supply their animals with unnecessarily large 

 quantities of albuminoids, and thereby not only make their 

 feeding unduly expensive, but in some cases may seriously 

 affect the general welfare of their stock. 



There is not yet sufficient reliable evidence to permit a 

 definite statement as to the relative feeding values of the 



