FEEDING STANDARDS AND FEEDING 



479 



The three last factors can be calculated from the known selling 

 price, and the proteid content and productive value of the feeds. 

 The bulk of the feed is of course measured by the total amount 

 of dry matter. It often happens that hays cost more per unit of 

 feeding value than concentrated feeds. In such cases, the cheaper 

 bulky feeds should be used, and the difference in nutritive value 

 compensated for by increasing the concentrates. The following 

 table shows the relative cost of nutrients on the Texas market 

 in 1910-11 : 



RELATIVE COST OF NUTRIENTS. 



Suppose a feeder who is using 6 pounds wheat bran at a cost of 

 $30.00 a ton, can secure corn at $30.00 and cottonseed meal at 

 $40.00. Would it pay to substitute? Six pounds wheat bran 

 contains 0.72 pounds proteids and 0.72 pounds productive value. 

 Three and one-half pounds corn would contain 0.72 pounds pro- 

 ductive value and 0.241 pounds proteids, or a deficiency of 0.48 

 pounds proteids. Replacing corn by cottonseed meal, 0.48 -r- 

 0.352 -- 0.068 =1.4 pounds. That is, 1.4 pounds cottonseed 

 meal and 3.5 pounds corn are equivalent to 6 pounds wheat bran. 

 The cost would be 6 x 1.5 9 cents for wheat bran; and for 

 the mixture, 1.4 x 2.0 = 2.8 cents for the cottonseed meal, and for 

 the corn 3.5 x 1.5 = 5.25 cents, a total of 8.05 cents for the mix- 

 ture or a difference of 0.95 cents, nearly one-ninth in favor of 



