CHAPTER VIII. 



FEEDING STANDAKDS CALCULATING KATIONS. 

 I. HISTORY OF FEEDING STANDARDS. 



At the beginning of the last century almost nothing was known 

 concerning the chemistry of plants and animals. At that time the 

 farmer gave his ox hay and corn without the least conception of 

 what there was in this provender that nourished the animals. But 

 science soon permeated every line of human activity, and agricul- 

 ture was benefited with all the other arts. Davy, Liebig, Boussin- 

 gault, Henneberg, Wolff, Lawes and Gilbert, and other great scien- 

 tists were early laying the foundations for a rational agricultural 

 practice based on chemistry, and animal feeding gained with the 

 rest. 



124. Hay equivalents. The first attempt to systematically com- 

 pare the feeding values of different feeding stuffs was by Thaer 1 

 of Germany, who in 1810 published a table of hay equivalents in 

 which meadow hay served as the standard. According to this 

 writer the amounts of various other feeding stuffs required to equal 

 100 Ibs. of meadow hay were : 



91 Ibs. clover hay 417 Ibs. rutabagas 



91 Ibs. alfalfa hay 602 Ibs. cabbages 



200 Ibs. potatoes 625 Ibs. mangels 



Naturally opinions on feed values varied, and so there were about 

 as many tables of hay equivalents as there were writers on the sub- 

 ject. 



125. The first feeding standard. Chemistry having paved the 

 way, Grouven 2 in 1859 proposed the first feeding standard for farm 

 animals, based on the crude protein, carbohydrates, and fat in feed- 

 ing stuffs. This, however, was imperfect since it was based on the 

 total instead of the digestible nutrients. 



126. The Wolff feeding standards. In 1864 Dr. Emil von Wolff, 

 the great German scientist, presented for the first time in the Ment- 

 zel & von Lengerke's Agricultural Calendar 3 for that year a table 



1 Landwirtschaft, New ed., 1880, p. 211. 



'Feeding Standard for Dom. Anim., Expt. Sta. Bee., IV; also Agricultur- 

 chemie, Kb'ln, 1889, p. 834. 



* Published annually by Paul Parey, Berlin, Germany. 



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