CHAPTER VII 



FEEDING STANDARDS CALCULATING RATIONS 



I. EARLY FEEDING STANDARDS 



In the preceding chapters we have considered the functions of the 

 various nutrients in the nourishment of animals and have studied the 

 general requirements for maintenance, growth, fattening, and the pro- 

 duction of work, milk, and wool. To guide the farmer in choosing 

 and computing rations for his stock, scientists have put these require- 

 ments into definite form thru the drawing up of feeding standards. 

 These are tables showing the amount of each class of nutrients which, it 

 is believed, should be provided for the best results in rations for farm 

 animals of the various ages and classes. 



At the beginning of the last century almost nothing was known con- 

 cerning the chemistry of plants and animals. The farmer then gave his 

 stock hay and grain without knowing what there was in this feed 

 that nourished them. But science soon permeated every line of human 

 activity, and agriculture was benefited along with the other arts. Davy, 

 Liebig, Boussingault, Henneberg, Wolff, Lawes and Gilbert, and other 

 great scientists were early laying the foundations for a rational agri- 

 cultural practice based on chemistry, and animal feeding gained with 

 the rest. 



153. Hay equivalents. The first attempt to express the relative value 

 of different feeding stuffs in a systematic manner was by Thaer 1 of 

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

 hay as the standard. According to this writer the amounts of various 

 other feeding stuffs required to equal 100 Ibs. of meadow hay in feeding 

 value 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 w r riters on the subject. 



154. 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 feeding stuffs. 

 This, however, was imperfect, since it was based on the total instead of 

 the digestible nutrients. 



155. The Wolff feeding standards. In 1864 Wolff, a famous German 

 scientist, presented the first table of feeding standards based on the 



'Landwirtschaft, New Ed., 1880, p. 211. 

 'Feeding Standard for Dom. Anim., Expt. Sta. Re., IV. 



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