XI.] FOOD RATIONS 2i7 



cheapness. Sometimes also we find that animals are 

 being grossly overfed, and this we can detect by finding 

 that the total number of starch equivalents fed is greatly 

 in excess of the number in a standard ration. 



This system of starch equivalents to represent the 

 relative value of the different feeding stuffs is really the 

 return to one of the earliest methods by which it was 

 proposed to bring these substances into comparison. 

 Early in the nineteenth century Thaer, one of the first 

 of the German agriculturists to apply science to the 

 feeding of animals, attempted to draw up a table of 

 what he called " hay values " for the different foods then 

 available, these hay values being the equivalents in 

 good hay of lOO lb. of the food in question. Thaer's 

 hay values, however, were almost entirely based upon 

 the amount of nitrogen contained in food, and it is 

 rather characteristic of the change that has passed over 

 the science of feeding stuffs to find that the new starch 

 equivalents upon which we now base our comparisons of 

 foods take no account of the nitrogen the food contains. 



A few examples may now be given of the use of the 

 starch equivalents in compounding rations. 



The following ration was given to heavy dray horses 

 working long journeys : — 



and it became desirable to replace the peas, which were 

 no longer obtainable cheaply. From Table XVII. we 

 learn that peas possess a starch equivalent of 70 and an 

 albuminoid ratio of i : i\. Now maize possesses a 

 starch equivalent of 68, so that they could be substituted 



