COMPUTATION Of RATIONS 



183 



How to Compute the Ration. — Let us suppose cotton-seed meal, 

 corn meal, wheat middlings, oat hay and rye straw are avail- 

 able. Our previous study has taught us that we should en- 

 deavor to supply 12 to 14 pounds of dry matter from roughage, 

 as roughage generally is our cheapest source of feed. We have 

 been taught that the amount of roughage should be limited be- 

 cause an animal can only properly consume a certain amount of 

 roughage. Rye straw and oat hay are the feeds which are 

 available as roughage. 



In Table IV we find that 100 lbs. of rye straw and oat hay 

 contain : 



Rye straw 



Oat hay 84.0 



Let us see what 8 lbs. of rye straw will furnish: 



92.9 X o-o8 = 7.432 pounds dry matter 

 0.63 X o-o8 := 0.0504 pound digestible protein 

 20.87 X o-o8 = 1.6696 therms of energy value 



Eight pounds of rye straw furnish 7.432 lbs. of dry matter. By 

 a simple calculation we find that 6 lbs. of oat hay will furnish 

 the remaining dry matter required from roughage. The amounts 

 for oat hay are arrived at in the same way as for rye straw. 



Dry matter 

 pounds 



Digestible 

 protein 

 pounds 



Energy 

 value 

 therms 



8 pounds rye straw 

 6 pounds oat hay . . 



Total 



7-432 

 5.040 



12.472 



0.0504 

 0.1554 



0.2058 



1.6696 

 2.2182 



3.8878 



We must supply the difference between what we have figured 

 for roughage and the requirement (1.7 lbs. digestible protein 

 and 12.975 therms of energy value) with the available concen- 

 trates (cotton-seed meal, corn meal and wheat middlings). 



