SELECTION OF FOOD. 57 



exercise directly increases the waste of tissue, we must 

 add to the amount of grain according to the degree of 

 labour, though, at the same time, allowing an unlimited 

 supply of hay, in order to comply with the conditions 

 just stated. The exceptions to this rule will be : when 

 the horse is in a state of enforced idleness ; when his 

 appetite is in a depraved or abnormal condition ; and 

 when he is required for immediate work. When a 

 horse's powers are fully taxed, he should be allowed as 

 much hay and suitable corn as he chooses to consume. 

 This now leads us to the pertinent question, " what 

 proportion should the nitrogenous matter in grain bear 

 to the starchy constituents ? " From the teaching of 

 experience, which here can alone direct us, we may 

 learn that, for moderate work, it should not exceed that 

 which is contained in oats, namely, 10 to 47 (about). 

 To find the maximum, we may assume a diet of four 

 parts of oats and one part of beans (as given in England 

 to hard worked animals), which will give us the propor- 

 tion of 10 to 38 (about). 



To determine the maximum amount of nitrogenous 

 food, I think we may safely assume it to be about that 

 contained in 20 Ibs. of oats, namely, 2Jlbs. (about). If 

 we are forced, by circumstances, to use a grain, such as 

 gram, or k&lthee, which is too rich in nitrogen, we 

 should do so at the expense of the starch, but should, 

 on no account, exceed the amount of nitrogen already 

 laid down ; for if we do so, the excess will tend to 

 produce the derangements of the system which have 

 been already mentioned. 



Eespecting the supply of fat, I am unable to say 

 anything more definite than I have done in the previous 



