6-1 THE PRACTICAL HORSE KEEPER. 



which, when introduced into the system, are transformed by 

 the process of mastication, digestion, and assimilation, into 

 material for the maintenance of animal heat, and to repair 

 waste caused by the unceasing functions of respiration and 

 transpiration. A portion of any excess in this class of con- 

 stituents taken with the food is stored up in the form of fat, 

 to be re-absorbed and appropriated whenever there is a 

 deficiency in the supply of non-nitrogenous matter to meet an 

 existing demand for it. The fourth column in the first, and 

 second column in the second, representing the relative pro- 

 portions of muscle-forming material in feeding stuffs, possess 

 especial interest to the horse-owner ; for upon a due supply of 

 nitrogenous matter in a form capable of being assimilated, the 

 reparation of nervous and muscular waste, and the function of 

 general nutrition, alone depend. Unless the food contains a 

 sufficient proportion of these substances, the body must be 

 inefficiently nourished, and physical strength diminished, even 

 if all the other elements of food are abundantly supplied. Un- 

 like the elaborations of starch and fatty matters, an excess of 

 nitrogenous material cannot be stored to meet future demands, 

 any superabundance being removed from the body by the 

 various processes of excretion. Should an excess of this material 

 be given for any length of time, and no requirement for it be 

 created by corresponding increase of work, disease must result. 



The woody-fibre or cellulose contained in varying propor- 

 tion in different kinds of provender, although possessing in some 

 degree a composition similar to the non- nitrogenous constitu- 

 ents, cannot be considered altogether as aliment. Its function 

 in the animal economy is to stimulate digestion and separate 

 the richer particles of the food. The ash and salines furnish 

 material for renewal of the bodily frame, and assist in the 

 elaboration of secretions. 



The amount of food constituents needed to maintain the 

 functions of the body in proper working oftier, without the 



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