78 PRINCIPLES OF FEEDING FARM ANIMALS 



dairy cows at least, and the same doubtless holds true also for other 

 classes of farm animals. Of the rations experimented with, only 

 those composed entirely of corn feeds (corn meal, gluten feed, and 

 cornstalks) proved satisfactory for dairy cows (see p. 166). 



Fifth, the local market prices of feeding stuffs are of the greatest 

 importance in determining which feeds to use; the conditions in the 

 different sections of our continent are so different in this respect as 

 to render generalization difficult. As a rule, nitrogenous concen- 

 trates are the cheapest feeds in the South and the East, and flour- 

 mill, brewery, and starch-factory refuse feeds the cheapest in the 

 Northwest. Where alfalfa or other leguminous crops form the main 

 dependence of farm animals for roughage, nitrogenous concentrates 

 need not be fed to the extent that is necessary where farmers depend 

 on mixed hay, corn fodder, and other non-nitrogenous forage crops 

 for feeding their stock. 



The feeding standards express the physiological requirements of 

 animals for a certain production. The economy of systems of feeding 

 based on the standards does not enter into consideration, nor is it 

 possible to formulate feeding standards of general or permanent 

 value that take into consideration the financial side of the question, 

 since the market prices of feeds vary in different places and at dif- 

 ferent times in the same places. But for the practical farmer the 

 cost of feeds is a factor of vital importance. It is of little help to 

 him to be told that he can secure a certain production of milk or meat 

 by a special system of feeding if the prices of the different feeding 

 stuffs called for make it impossible or unprofitable for him to adopt 

 them in his feeding operations. However, the standards place before 

 the feeder an ideal which he may approach as nearly as the special 

 conditions by which he is surrounded will allow. The relative cost 

 of different feeding stuffs must always be considered, and the choice 

 of feeds with which to supplement home-grown forage crops and 

 grain must be made accordingly. 



QUESTIONS 



1. Explain how a ration is calculated according to (a) the Wolff-Leh- 



mann standard ; ( 6 ) the Armsby standard. 



2. Discuss the relative value of these two standards for (a) dairy cows; 



(6) fattening steers. 



3. Formulate rations for a 1000-pound dairy cow producing 20 pounds of 



4 per cent milk, according to (a) Wolff -Lehmann, (6) Armsby stand- 

 ards, using the following feeding stuffs: Mixed hay, oats, and wheat 

 middlings. 



4. Explain the method of calculating nutritive ratios; give an example. 



5. State the limitations of feeding standards, and give at least four points 



to be considered in formulating rations for farm animals. 



6. What is the difference between a physiological standard and a practical 



feeding standard? 



