CHAPTER XVI 

 RELATIVE VALUES OF FEEDING STUFFS 



As soon as live stock husbandry emerged from the pastoral 

 stage and man began to store up forage for the winter or to 

 utilize the products of his cultivated land for feeding his do- 

 mestic animals, the question of the relative values of the dif- 

 ferent feeding stuffs necessarily arose. As agriculure has 

 gradually become more intensive and as the variety of natural 

 materials and of technical by-products available has increased, 

 the question has grown in importance, the traditions of prac- 

 tice based on the experience of earlier investigations have been 

 recognized to be insufficient guides, and much effort has been 

 put forth to replace these traditions by exact knowledge. 



i. DIRECT COMPARISONS OF FEEDING STUFFS 



700. Hay values. A natural and logical method of inves- 

 tigation was to feed the materials in question to animals and 

 compare the amount of increase or of milk which was secured. 

 Good meadow hay was universally regarded as a complete feed, 

 suitable for practically all purposes. Hence it was naturally 

 taken as the standard and the effort was made to establish from 

 the results of experience and experiment what amounts of dif- 

 ferent feedstuffs would replace a unit weight of hay. In this 

 way arose the tables of so-called hay values. 1 The first of these 

 was that published by Thaer in Germany in 1809, based chiefly 

 on the early chemical analyses of Einhof in which the con- 

 stituents soluble in water, alcohol, dilute acids and dilute alka- 

 lies were determined. The sum of all these ingredients, with- 

 out distinction as to kind, was taken to represent the nutritive 

 value, and the hay values were computed in proportion to them. 



1 Compare Henneberg, Uber den Heuwert der Futterstoffe ; Beitrage zu Fiitter- 

 ung der Wiederkauer, Heft i, 1860, pp. 1-16; and von Gohren, Naturgesetze der 

 Fattening, 1872, pp. 286-305. 



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