216 



FARM MANAGEMENT 



139. Feed units. In order to compare the feeding 

 value of different feeds, various feed units have been used. 

 The best one for American conditions considers corn as 1 

 and expresses the value of other feeds in terms of their 

 corn equivalent. Such a system is of value in helping 

 one to determine which feeds to buy at present market 

 prices. Of course it cannot be followed blindly. In 

 order to be able to compare the amounts of feed used by 

 different animals or herds, some such system is necessary. 

 The following table represents the comparative values of 

 different feeds as based on many feeding trials with 

 dairy cows. To a limited extent, a pound of one of the 

 given feeds may replace one of the other feeds to which 

 it is equivalent without decreasing the milk yield. 



If a cow is fed 40 pounds of silage, 10 pounds of mixed 

 hay, and 9 pounds of grain, made up of a mixture of equal 

 parts of Ajax flakes, corn meal, and wheat bran, 19.86 

 feed units would be used. The method of calculating is 

 as follows : 



Of course there is great variation in the different 

 grades of hay, corn silage, and similar products. The 

 approximate range of variation is shown in the last column 

 of Table 31. There is also poor corn. The unit is for good 

 corn. If feeds are poor, an allowance may be made. 



