HUNGER AND THIRST. 125 



mixture of food. Both hay and straw furnish a liberal 

 supply of fibre and ash. 



MAXIMUM AMOUNT OF NITROGENOUS MATTER IN FOOD. 



The foregoing considerations suggest the question : what is 

 the maximum amount of nitrogenous matter which a hard- 

 working horse can eat daily without injury to his health ? 

 From practical experience in India of feeding horses on gram 

 (pp. 169 and 170), which is a highly nitrogenous food, I know 

 that not more than 10 Ib. of this grain can be consumed daily 

 by an ordinary saddle horse without its upsetting his diges- 

 tion and "heating" his system. In 10 Ib. of gram there are 

 about 2 Ib. of nitrogenous matter, which we may take as a 

 maximum for average sized animals. That quantity would 

 be found in about 18 Ib. of oats, 20 Ib. of maize, or 7^ Ib. 

 of beans. This maximum might be slightly increased in 

 exceptional cases. In the East, highly nitrogenous foods, 

 like gram, are used by sensible people as an exclusive grain 

 food, only when they are unable to obtain more suitable grain, 

 such as oats or maize. An addition of bran, owing to the 

 comparatively large percentage of mineral matter it con- 

 tains, will be desirable when highly nitrogenous grain is given 

 to a horse in considerable quantities. In such cases, a par- 

 ticularly liberal supply of hay or grass should be allowed ; 

 because these articles of fodder contain a large proportion 

 of ash. 



HUNGER AND THIRST. 



We may define hunger as appetite (p. 104) in excess. 



Thirst is the desire to drink, caused by functional necessity, 

 and accumulation, in the body, of decomposition products 

 which require water for their removal. Colin tells us that if 

 a horse is thirsty while he is eating, he will chew his food 

 slowly and the flow of saliva will be languid. He will soon 



