26 



BULLETIN 459, U. S. DEPARTMENT OF AGRICULTURE. 



The first step is to compute, in precisely the same way as in the 

 previous example, the estimated requirements of these cows per day 

 as follows: 





Digestible 

 protein. 



Net-energy 

 value. 





Pounds. 

 0.50 



1.25 



Therms. 

 6.00 



For 24 pounds of milk: 



Protein 24X0. 052 





Net energy 24X0.29 



6.96 











1.75 



12.96 







The amount of silage and clover hay available will furnish, ac- 

 cording to the table on pages 11-13, the following amounts of dry 

 matter, digestible protein, and net energy value : 



Kind and amount of feed. 



Total dry 

 matter. 



Digestible 

 protein. 



Net energy 

 value. 



Corn silage, 32 pounds 

 Clover hay, 8 pounds. 



Total 



Pounds. 

 8.42 

 6.97 



Pound. 

 0.19 

 .39 



Therms. 

 5.09 

 3.09 



15.39 



.58 



8.18 



The question now is what feeding stuffs is it most economical to 

 buy (or to refrain from selling if in stock) to complete the radon. 

 The first step in deciding this question is to compare the various feeds 

 as sources of energy and see which one furnishes a unit of net energy 

 value at the lowest price. This computation gives the following 

 results : 



Kind of feed. 



Cost of 100 

 pounds. 



Energy 

 value 

 of 100 



pounds. 



Cost of 



1 therm 



net energy 



value. 



Oats 



Corn meal 



Wheat bran 



Wheat middlings 



Dried brewer's grains. . . 



Gluten meal 



Cottonseed meal 



Old-process linseed meal 



SI. 25 

 1.25 

 1.95 

 1.20 

 1.15 

 1.35 

 1.50 

 1.65 



Therms. 

 67.56 

 88.75 

 53.00 

 75.02 

 53.38 

 84.15 

 90.00 

 88.91 



Cents. 

 1.85 

 1.41 

 1.98 

 1.60 

 2.15 

 1.60 

 1.67 

 1.86 



Evidently, if it were simply a question of supplying energy to the 

 animals, we should use corn meal, since that supplies a unit of energy 

 at a much lower price than any of the other feeding stuffs. If it 

 were thought desirable to add variety to the ration, wheat middlings 

 would obviously be our next choice. 



