CIRCUMSTANCES AFFECTING DIGESTIBILITY 101 



horse to perform work ; hence it is reasonable to suppose 

 that the harder or more difficult the work is, the greater 

 will be the amount of food required (within limits). If, 

 however, a food difficult to digest were given to supply 

 the energy required for work, a larger proportion of 

 the available nutrients would be required to overcome 

 the mechanical difficulties of digestion before there 

 would be any nutrients available for external mechani- 

 cal work. Hence the importance of a concentrated 

 and easily digestible ration when horses are doing 

 hard work. 



Experiments do not show that a larger proportion 

 of the food is digested when horses are at work ; in 

 fact, as the labour increases in intensity the reverse is 

 the case. At the same time, a richer diet should be 

 given and a larger amount of nutrients fed. 



XVI. GENERAL CONSIDERATIONS IN COM- 

 POUNDING RATIONS. 



The general requirements of the animal vary with 

 the kind of animal, its age, whether it is being kept in 

 store condition or for purposes of production (meat, 

 milk, or work). In order to meet these requirements 

 the animals must be supplied with food ; and in utilising 

 the artificial foods for this purpose, one should, strictly 

 speaking, keep in mind the following points : 



(a) The chemical composition and balance of 



nutrients. 



(b) Digestibility of food used, and the albuminoid 



ratio. 



(c) Utilisation of home-grown stuffs to the best 



advantage. 



