78 PRINCIPLES OF FEEDING FARM ANIMALS 



receiving a good grade of alfalfa or other rich coarse feeds will 

 not need more than one-half of this amount of grain feed. 



Third, the ration should conform to the system of farming fol- 

 io-wed, and this should be arranged with a view to growing on the 

 farm, if possible, all the roughage and most of the concentrates 

 which the stock are to' receive, so that the farmer may be largely 

 independent of the feed market with its fluctuating prices. 



Fourth, the rations are preferably composed of feeds of different 

 origin, so that, especially, the protein substances are supplied from 

 different sources. Experiments with cows fed rations balanced 

 from restricted sources (corn, wheat, or oat products' only) at the 

 Wisconsin Experiment Station 2 illustrate in a striking way the 

 necessity of furnishing a variety in the make-up of rations for 

 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). For 

 milk-producing and growing animals the feeding of legumes has been 

 found important, to furnish an ample supply of calcium and phos- 

 phorus in the rations fed. It has likewise been found necessary to 

 include some feeds containing growth-promoting vitamins in the 

 rations fed young animals, to insure normal healthy growth. 



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 o*r 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 low-protein forage crops. 



QUESTIONS 



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



mann standard; (ft) 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 

 standards, using the following feeding stuffs: Mixed hay, oats, and 

 wheat middlings. 



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



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



feeding standard? 



6. State the limitations of feeding standards;, give at least four points 



to be considered in formulating rations for farm animals. 



2 Research Bulletin 17 ; Bulletins 275, 287 ; Jr. Agr. Science 10, p. 175. 



