THE FEED REQUIREMENTS OF FARM ANIMALS 127 



Armsby standard, one adds to the requirements for mainte- 

 nance, 0.05 pound of digestible protein and 0.3 therm of net 

 energy for each pound of 4 per cent milk produced. For 

 example, one wishes to calculate a ration for a 900-pound 

 cow giving 22 pounds of approximately 4 per cent milk. 

 According to Table 34 of the Appendix, the requirement is 

 as follows : 



As a trial ration, we will assume 3 pounds of. ground corn, 

 40 pounds of corn silage, and 15 pounds of clover h:.iy. 

 This ration contains the following nutrients : 



Obviously this ration is too high in dry substance and energy. 

 Consequently, 10 pounds of silage are deducted from the 

 ration, which then has the following composition: 



