XI.] FOOD RATIONS 219 



may assume that the ration is well above the safety 

 limit, and that the maize can be substituted for the 

 peas without affecting the horses. Instead of calculat- 

 ing out the albuminoid ratio of the whole, we might 

 have found how much digestible protein the new ration 

 contained, as follows : — 



2-96 



Thus the horse would be getting nearly 3 lb. of digestible 

 protein per diem, and Table XXIII. shows that a horse 

 in heavy work requires 2 lb. per diem per 1000 lb. 

 live weight. Thus, 3 lb. would be sufficient if the horses 

 in question did not weigh more than 1 500 lb. To take 

 another case, a fattening ration for cattle contained : — 



Lb. 



Swedes . . . .84 



Hay .... 12 



Linseed Cake ... 5 



and it was desired to substitute cotton cake and barley 

 meal for the linseed cake. Five pounds of linseed cake 

 is equivalent to 5X76-Moo=3-8 lb. starch; it also 

 contains 5X25-^-ioo=i-25 lb. protein. Barley has a 

 starch equivalent of 74 and 9 per cent, of digestible 

 protein, so that 2 J lb. of barley meal would be equivalent 

 to 2jx-74= 1-65 lb. starch, and would contain -22 lb. of 

 digestible protein. Three pounds of decorticated cotton 

 cake with a starch equivalent of 71 and 34 per cent, of 

 digestible protein would have a starch equivalent of 



