156 CONTINUOUS CROPPING 



not be here described, is calculated from the total 

 amounts of digestible albuminoids, fats, and carbo- 

 hydrates in a food, and hence enables us at once to see 

 the nutritive value of a food without referring to the 

 amounts of the particular food ingredients which the 

 food contains. 



THEORY AND PRACTICE — A SHORT CIRCUIT 



A study oi the foregoing is useful in order to get a 

 thorough grip of the principles underlying the science 

 of feeding. In practice there is not the slightest need 

 to worry about the percentage of digestible oil and 

 carbohydrates, or to calculate albuminoid ratios in the 

 manner described. Neither is there any need, as nearly 

 all text-books state there is, to study the amount of 

 dry matter or digestible fibre in a ration. 



All that need be considered by the practical man in 

 making up a ration is the amount of digestible albumi- 

 noids and the starch value of a ration. If these two 

 things are correct, there is bound to be a sufficiency of 

 non-albuminous food and dry organic matter in any 

 practical ration, a fact which seems to have been lost 

 sight of by writers of scientific text-books. 



Further, by only considering the two factors 

 mentioned and also by giving the actual weight of 

 digestible albuminoids contained in, and the starch 

 value of, such quantities of foods as are usually used in 

 practice (instead of giving the percentage composition 

 only as the text-books do) we can make a short circuit 

 in the calculation of food rations. In short, the whole 

 science of compounding rations can be boiled into such 

 a simple and brief calculation, that any man, even a 

 farm labourer, can use the system. 



We now give a table showing the total amounts of 

 digestible food ingredients, and the starch value of 

 different foods. The quantities of food stated are such 



