134 FEEDS AND FEEDING 



duction is higher in each ease, as already pointed out. In total digestible 

 nutrients he agrees very closely with Haecker. As the Eckles and Armsby 

 standards are expressed in digestible true protein (not crude protein) 

 and therms, they can not be compared directly with the standards of 

 Haecker and Savage. We may, however, compare these standards with 

 the others in the following manner : In such a ration as 20 Ibs. clover 

 hay, 4 Ibs. corn, and 4 Ibs. wheat bran, we would find that about one-third 

 of the total digestible crude protein is in amid form (11) and hence not 

 included in Eckles' figure for digestible true protein. With rations in- 

 cluding green forage or silage, the proportion of true protein will be still 

 lower. It is evident, then, that if Armsby 's figures for true protein were 

 converted into crude protein they would be fully as high as those of 

 Savage's and that Eckles' figures would be even higher, when applied 

 to ordinary rations. As about 1.1 to 1.2 Ibs. total digestible nutrients 

 have a net energy value of 1 therm in the ordinary rations used for 

 dairy cows, it will be found on computation that Eckles' standards call 

 for about the same amount of total nutrients as the standards of Haecker 

 and Savage for milk low in fat, but up to one-fifth more for milk high 

 in fat. Armsby 's standards advise less nutrients than any of the other 

 standards, requiring from 1 to 3 Ibs. less concentrates to balance, the 

 ration, depending on the production of the cow, than the Savage or 

 Haecker standards. In a trial by Morrison, Humphrey, and Putney at 

 the Wisconsin Station 20 cows fed enough concentrates to meet the recom- 

 mendations of the Savage standards produced slightly more milk and 

 fat than when fed only enough concentrates to meet the requirements as 

 stated by Armsby, but milk and fat were produced slightly more eco- 

 nomically on the Armsby rations, due to the fact that at that time (1918) 

 concentrates were unusually high in price. (569) 



From these results we may conclude that it is necessary to feed dairy 

 cows as much concentrates as are required to meet the recommendations 

 of the Savage or Haecker standards when the object is maximum pro- 

 duction, as in the case of cows on official test. It is also economy to 

 feed a liberal concentrate allowance when concentrates are relatively low 

 in price compared with hay and other roughage. On the other hand, 

 when concentrates are expensive compared with roughage, the most 

 economical production, but not the maximum production, can be secured 

 by feeding no more concentrates than are required to meet the recom- 

 mendations of the Armsby standard. The amount of protein and the pro- 

 portion of concentrates to feed dairy cows are discussed further in 

 Articles 194, 197-8, 569, and 645-6. 



VIII. MORRISON FEEDING STANDARDS 



187. Methods of computing rations compared. In this chapter it has 

 been pointed out that the valuation of feeding stuffs for productive 

 . Bui. 323, pp. 7-8. 



