MAINTENANCE FEED 173 



the calculation would be made as follows : 100 pounds of cocoanut cake contain 

 •16.3 pounds of digestible albumen and 76.5 pounds starch value. Thus 1 pound of 

 digestible albumen would be furnished by 100 pounds divided by 16.3^.14 pounds of 

 cocoanut cake. Such a large quantity of one ingredient, especially of this character, 

 would not be at all suitable for the purpose. It would be much better to use a 

 mixture of two or three concentrates, selecting some with a lower, others with a 

 higher albumen-starch ratio, so that the ratio of the mixture would be the same or 

 nearly the same as that required. 



Supposing that we should select — 



Peanut cake with 38.7 percent digestible albumen and 75.7 percent starch value; 

 Rice feed meal with 6.0 percent digestible albumen and 68.4 percent starch value. 



To solve this algebraic problem, let .*• equal the amount of peanut cake and y the 

 amount of rice feed meal which together are necessary to furnish the deficient 1 

 pound of digestible albumen and 3.5 pounds of starch value; then — 



38.7 6 



1 (the desired albumen)= x -\- y 



100 100 



75.7 68.4 



3.5 (the desired starch value)=: .r + y 



100 100 



To eliminate the fractions, mutliply the equations by 100, thus: 

 100 = 38.7^ + 6 y 

 350 = 75.7x-\-68Ay 



By multiplying the upper equation by 68.4 and the lower equation by 6 and sub- 

 tracting one from the other for the elimination of y, thus : 

 6,840 = 2,647.08Ar + 6 X 68.4^; 

 2,100= 454.2 x-\-6X 68.4y 



4,740 = 2,192.88.1- 

 4,740 



x^ ^=2.162 (pounds of peanut cake). 



2,192.88 



Having found the value of x, that of y is easily determined by a new equation 

 with X expressed in known terms, thus : 

 100 = 38.7;ir + 6y 

 100 = 83.6 +63; 

 63,^100 — 83.6 = 16.4 

 3,= 16.4 -i- 6:= 2.7 (pounds rice feed meal). 



The required amounts of digestible abumen (1 pound) and starch value (3.5 

 pounds) will be contained in 2.16 pounds of peanut cake and 2.7 pounds of rice feed 

 meal. These amounts should be added to the ration under consideration. 



B. Special Feeding 



I. Maintenance Feed 



1. Maintenance rations for oxen at rest in the stable, per 1,000 pounds 

 live weight per day, with temperature at 53.6 to 61.25° F. (according to 

 Kellner) should contain on an average 15 to 21 pounds of dry matter, 



