FEEDING DAIRY CATTLE 101 



pou ads of milk testing 4.5 per cent fat. According to the 

 preceding table the maintenance requirement would be as 

 follows : 



Digestible protein .56 pounds 



Energy 6.60 therms 



1 or the production of 30 pounds of 4.50 per cent milk 

 the 'e would be needed : 



Digestible protein (30 X .058) 1.74 pounds 



Energy (30 X .33 ) 9.90 therms 



The total requirements then are as follows : 



The problem is to find a ration that contains this amount 

 of digestible protein and has this energy value. Other 

 problems also enter into the question, such as bulk and the 

 comparative cost of the several feeds available. In cal- 

 culating a ration we always begin with the roughage, since 

 on most farms considerable roughage is on hand that should 

 be used to the best advantage, and, as already pointed out, 

 the cow is adapted for consuming coarse feeds and must 

 have a certain bulk in her ration at all times. We will as- 

 sume that on the farm where the foregoing ration is to be 

 fed, corn silage, clover hay, and corn are on hand, and wheat 

 bran and cottonseed meal may be purchased if necessary 

 to provide the proper ration. 



