ECONOMIC FEEDING OF DAIRY COWS. 71 



40 pounds. To adjust the ration to the varying needs of cows is where 

 we encounter difficulties under the feeding standards. One tells us that 

 we should feed 2.5 pounds of protein daily, another proposes 2.15, another 

 tells us to feed 1.6 of a pound of protein when a cow yields 11 pounds of 

 milk, 2 pounds when yielding 16.5 pounds of milk; but what 1 should be fed 

 for intermediate yields is not stated. Just at the critical point where a 

 feeder needs some definite guide he is left to shift for himself. If it is per- 

 missible to state that a cow requires 1.6 pounds of protein when yielding 4 

 11 pounds of milk daily, the license will apply to factors applicable to any 

 yield of fairly similar milk. Having found the nutrients required for 

 a pound of milk and the maintenance of the body, rations can readily be 

 adjusted, approximately to the needs of each animal. 



Having found a ration adapted to a cow yielding 10 pounds of milk, 

 let us adjust it to a cow yielding 15 pounds. Taking the footings of the 

 first ration we must select some food stuff or some mixture that will pro- 

 vide five times the nutrients required for one pound of milk, or, pro. .25, 

 C. H. 1.10, fat .09. By trial it is found that 1 pound each of bran and 

 shorts or bran and middlings will answer. Turning again to the table 

 giving the composition of feeding stuffs, we find that a pound of bran con- 

 tains .129 of a pound of protein, .40 of carbohydrates and .03 of fat, and 

 that 1 pound of shorts contains .122 of protein, .50 of carbohydrates and 

 .04 of fat. Adding this to the ration we have the following: 



/ Digestible N 



Lbs. Pro. C.-H. Fat 



Ration for 10 pounds of milk 1 . 26 9 . 68 .41 



Bran 1 .129 .40 .03 



Shorts 1 .122 .50 .04 



Ration for 15 pounds of milk 1.51 10 . 58 .48 



In like manner the ration can be adjusted to any yield of milk by add- 

 ing at the rate of two pounds of the mixture to each additional 5 pounds 

 of milk yielded. In general feeding practice, one and a quarter pounds 

 of the grain mixture to three pounds of milk yielded will bring satisfactory 

 results. 



If the roughage in the ration will approximately provide the nutrients 

 needed for food of maintenance, then the grain mixture may be so pro- 

 portioned that 2 pounds of it will contain the nutriment needed for 5 pounds 

 of milk. 



1.77 11.23 .56 



The roughage and 8 pounds of the grain mixture will answer for a cow 



