PLAN OF INVESTIGATION. 17 



PLAN OF THE PRESENT INVESTIGATION. 

 MI.THon 01 1 SI IMA II. \G THE RELATIVE FOOD VALUES OF GRAINS. 



While the direct experimental method is without question the one 

 on which to rely for the determination of the maintenance or produc- 

 tion values of feeding stuffs, it is not always possible to make such 

 investigations on living animals with a large number of foods. Such 

 direct experiments have heen made both in this country and Europe 

 by the inve>tigator> previously mentioned, and their work embraces 

 quite a number of different animals and foods. Taking the results 

 of these inve>tii:ation^ as a basis, and using the factors that have 

 thus been found to apply to certain animals and certain foods, it 

 is p>ihle to calculate from simple analytical data the production 

 values of a laiver number of samples of feeding stuffs than could 

 po^ihly be determined in any other way. The production values and 

 nut ritive rat i<>-<>f foods thus determined form the best basis now avail- 

 able for a comparative or even for an actual valuation of stock foods. 



In the present investigation of the feeding value of cereal grains this 

 method ha> been u^ed to determine the relative value of the different 

 grails studied. It U not claimed that these results are as accurate 

 as those that \\ould hav- been obtained had careful feeding experi- 

 ments been made \\ith each sample, but a: 1 , tlie factors used in calcu- 

 lating the final value> are ba>ed upon average results with each group 

 or < l.i D studied, the calculated values are the best obtain- 



able from siinpl.- analytical n^ults. Neither total fuel value, total 

 metaholi/ahle . nor comparative nutritive value have been 



calculated. hecau>e \\ith grains, where the chief object in feeding is 

 the production >f flesh, the production value and nutritive ratio 

 express the values heM . A- -tilled previously, the factors used are 

 tho-e L r i\eii by Krllnn . .\eept in the case of sorghum, to which 

 material the iveent iv>ult> of Tangl are more applicable. For coeffi- 

 cient > of diiT'-tibility as given in Table II (p. 9), figures for the 

 identical Bpeciee of cereal were u-e.l when this was known without 

 question, as \\ith oats, barley, rye, wheat, and maize. For emmer 

 and einkorn the figures are those for the German " Spelzweizen," 

 which is identical \\ith one. but not with the other. The two grains 

 are, however, BO >imilnr that little error is probably introduced. 

 nonsaccharine sorghums, the figures are those for "Dari," and 

 for pro.,.. Tangl's figure-* for " Besenhirsekorn," fed to oxen. For 

 production value- the factors of Kellner given in Tables VI and VII 

 (pp. lo and 14) are Used. 



DESCRIPTION OF MATERIAL EXAMINED. 



The material examined in the present investigation consists of 

 samples of different grains that have been under field trial by the 

 Oilice of drain Investigations of the Bureau of Plant Industry dur- 

 64971 Bull. 12009 2 



