102 THEORY OF FEEDING. 



because salt being an excisable article in India, the amount 

 of its consumption can be obtained with a fair degree of 

 accuracy, and as the vast majority of the inhabitants of that 

 country are very poor, they are forced to practise rigid and 

 often unhealthy economy in its use. These comparative con- 

 siderations will, I think, support my contention that a horse 

 fed exclusively on hay or grass should have a daily supply 

 of not less than 3^ oz. of common salt. Continuing this 

 line of calculation, we are enabled to construct the following 

 approximate table : 



Approximate amount of corn- 

 Nature of fodder. mon salt required to be 



added to each loolb. 

 Oats, maize, and barley . . . . . . 5 oz - 



Beans, peas, and gram . . . . . . 17 ,, 



Meadow hay . . . 12 ,, 



Red clover hay . . . . . . . 23 ,, 



Lime is required chiefly for the building up of bones, which 

 process is active in young animals, but is slow in adults, because 

 bone is a comparatively stable tissue. Lime is far more easily 

 absorbed from vegetable food than when given as a mineral 

 addition to the food, as for example, in the form of lime- 

 water or chalk. Hence, if the soil that produces grass which 

 is given to young horses is poor in lime, it is well to make up 

 the deficiency through the grass by manuring the ground with 

 bone manure or lime. Soluble phosphate of lime is the 

 form in which an artificial supply of lime is most easily taken 

 up by the system. 



As maize is poor in lime and other mineral matters, it 

 is not a suitable food for young horses ; although it answers 

 fairly well for adult horses. Oats are much richer in 

 lime than maize, barley, or wheat. Hay, and particularly 

 lucerne hay and clover hay, contain a large percentage of 

 lime. 



Deficiency in the mineral matter of food is not an unfrequent 



