44 THE ECONOMICS OF FEEDING HORSES 



ing all these, is the brain and nervous system. Now, 

 all these processes require the expenditure of energy, and 

 this has to be supplied by the food. The amount of 

 food required for this purpose is called the maintenance 

 diet, and many experiments have been performed in 

 order to determine the suitable quantity. It will be 

 evident that the maintenance ration must be such that 

 the animal loses no weight, and puts on no fat or 

 increase of flesh, but remains in a state of equilibrium. 

 In the case of the horse, the amount of food necessary 

 for a resting animal should be known, for not only is it 

 unnecessary, but it is actually dangerous to health, to 

 feed the same amount to a resting as to a working 

 animal. Now, it is quite possible to maintain an animal 

 on one foodstuff alone, if given in suitable quantity ; but 

 it is rarely, if ever, economical to do so, for digestion of 

 the various constituents is almost always improved in a 

 mixture properly arranged. Again, in the horse, experi- 

 mental determination of a maintenance diet is compli- 

 cated by the fact that the animal during the experimental 

 period needs some exercise, and, of course, this increases 

 the food demand. This circumstance, however, corre- 

 sponds to the actual conditions when feeding resting 

 horses for any length of time, since they, too, must have 

 exercise. 



Taking a horse weighing 1,000 lbs., various estimates 

 have been arrived at, of which the most carefully deter- 

 mined are those by Wolff, Zuntz, Grandeau, and Kellner. 



Wolff's estimate is 6*78 lbs. of digestible organic 

 matter, exclusive of digestible crude fibre. Grandeau, 

 experimenting with three cab-horses for fourteen months, 

 came to a very similar conclusion — namely, 6*75 lbs. 

 digestible nutrients per 1,000 lbs. Zuntz, with more 



