352 AGRICULTURAL CHEMISTRY 



amount of nutrients in a dairy ration should vary with 

 the milk yield, as given in the table of feeding standards, 

 but it is not necessary to adhere too closely to the figures. 



In the calculation of a dairy ration, it will be found 

 that when ordinary foods are combined, the amount of 

 ether extract or crude fat will exceed the figures given 

 in the table. Provided the ration contains the requisite 

 amount of digestible protein, and does not yield more 

 than 32,000 calories, there is no objection to the crude 

 fat amounting to 0.6 pound per day. It should not, 

 however, in an average ration, exceed 0.75 pound. 



477. Selection of Foods for Dairy Cows. The amount 

 of grain which a dairy cow should receive varies from 7 

 to 12 pounds per day. Occasionally 15 pounds can be 

 fed economically, but, as a rule, medium grain rations of 

 from 7 to 12 pounds produce milk and butter more eco- 

 nomically than either light or heavy rations. As in beef- 

 feeding, when more than 12 pounds per day of grain are 

 fed, the additional amount is not used economically and 

 is generally a loss. The coarse fodder in a dairy ration 

 may vary from 1 8 to 50 pounds per day, according to the 

 amount of water present in the foods. The ration should 

 contain from 25 to 30 pounds of dry matter. When 

 silage is fed, 20 to 40 pounds may be used because of the 

 large amount of water present. In the feeding of roots, 

 from 15 to 20 pounds per day will be found economical. 

 In feeding dairy cows, it is not desirable to restrict the 

 ration to one grain or milled product. Better results are 

 secured from a mixture of two or three grains. No 

 great differences have been observed in the milk-producing 



