98 A STUDY OF FARM ANIMALS 



As an example, we will take the case of a cow weighing 

 1,200 pounds, producing 30 pounds a day of milk testing 4.0 

 per cent fat. Digestible Total digestible 



A 1,000-pound cow requires for t> rotein nutrients 



maintenance 0.70 Ib. 7.925 Ibs. 



A 1,200-pound cow requires for 



maintenance 0.84 Ib. 9.510 Ibs. 



If one pound of 4.0 per cent milk requires 0.054 0.065 

 pound protein, then 30 pounds would require 30 times 0.054 

 0.065 which would be 1.62 1.95 pounds protein. 



If one pound of 4.0 per cent milk requires 0.346 pound 

 digestive nutrients, then 30 pounds would require 30 times 

 0.346, or 10.38. 



Adding these to the maintenance ration, we find that the 



required standard would be: D i gest iUe Total digestible 



protein nutrients 



For maintenance 1,200-lb. dairy cow. .0.84 Ib. 9.51 Ibs. 



To meet demands 30 Ibs. 4.0% milk.. 1.62-1.95 Ibs. 10.38 Ibs. 



Total required 2.46-2.79 Ibs. 19.89 Ibs. 



Thus we ascertain that a 1,200-pound cow producing 30 

 pounds of milk a day containing 4.0 per cent fat should 

 receive daily a ration containing from 25 to 30 pounds of 

 dry matter, 2.46 to 2.79 pounds of digestible protein, and 

 19.89 pounds total digestible nutrients, with a nutritive ratio 

 from 1:7 to 1:8. 



The adjustment of rations to the standard is not usually 

 difficult. An increase in dry matter and carbohydrates is 

 easily secured with the hays or most of our common feed 

 stuffs. If a ration needs some adjustment in the protein, then 

 some concentrate such as soy beans, cottonseed meal, lin- 

 seed oil meal, or tankage may be selected. The cost of the 

 feed is an important matter, and should be carefully con- 

 sidered. Some feeding stuffs, like cottonseed meal, oil meal, 

 or tankage, that are not common in all localities, are easily 

 purchased and shipped in by freight, and may often be used 

 with much advantage and profit. These are high-class con- 



