FEEDING DAIRY CATTLE 



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constituents. The next question is, how much of each 

 constituent is needed to supply what the cow must have to 

 enable her to produce a good flow of milk. This problem 

 has been worked on for many years by able investigators, 

 and a fairly accurate knowledge of the subject has resulted. 

 A si atement of the food requirements of the animal is known 

 as i\ feeding standard. 



The first feeding standard to come into use in a practical 

 way was one prepared by Wolff, an eminent German in- 

 vesiigator. A later revision by Lehmann, known as the 

 Woiff-Lehmann standard, has been widely used. A standard 

 prepared in this country by Hsecker has also met with much 

 favor. The most recent feeding standard to come into use 

 was prepared by Dr. Armsby of the Pennsylvania Exper- 

 iment Station and is based upon his own extensive investi- 

 gations and those of Kellner in Germany. He bases this 

 standard upon the amount of digestible protein, and the 

 production value, or energy value, of the feed. He uses the 

 term " therm " to represent the energy or heat value re- 

 quired to raise 1000 kilograms of water one degree centi- 

 grade (1000 calories). 



He first estimates the protein and energy required for 

 maintaining the animal, and to this adds the amount of each 

 necessary to supply what is needed for the milk. The 

 maintenance requirements for cattle are given as follows : 



