6 THE ECONOMICS OF FEEDING HORSES 



Thus, in feeding an adult working horse the diet must 

 be so arranged as to supply — 



(1) The actual loss of tissue due to wear and tear of 

 the body, looked upon as a machine. 



(2) Material corresponding to the fuel supplied to an 

 engine for the production of energy. 



Under (1), the chief loss is in the muscles and other 

 nitrogenous tissues, and must be made good by an 

 equivalent amount of protein. 



For (2), is required sufficient fat and carbohydrate, 

 with or without protein for : (a) maintenance — i.e., body 

 heat, energy to carry on the vital processes — circulation, 

 respiration, digestion, secretion, etc. ; and (/3) the pro- 

 duction of useful external work. 



This must be done with the least waste and at the 

 lowest cost ; and in order to secure this economy it is 

 obvious that the various constituents of the food must 

 be supplied in such proportions as are suitable to the 

 animal and its special requirements — in other words, the 

 constituents of the food must be properly balanced. 



In the following pages an attempt is made to show 

 what data are necessary for arranging rations for horses, 

 and how, by a careful study of the animal's needs, the 

 cost of the different foodstuffs, and their nutritive values, 

 the best results may be obtained at minimum cost. 



