452. Journal of Agricultural Research voi. in, no. 6 



CONCENTRATES 

 Armsby and Fries: Therms. 



Maize meal 3- 80 



Wheat bran 3-99 



Grain mixture No. 2 3-88 



Average 3. 89 



Grain mixture No. i 3.91 



Hominy chop 4. 08 



Average 4. 00 



Kellner and Kohler: 



Beet molasses 3-47 



Starch 3- 60 



Wheat gluten 4. 79 



Tangl (44), Tangl and Weiser (45), and Zaitschek (50) have also deter- 

 mined the metabolizable energy of a number of feeding stuffs for cattle, 

 the methane being estimated from the amount of digestible carbohydrates, 

 with the following results, which are very similar to those just reported : 



Metabolizable energy per kilogram of digestible organic matter: Tangl's experiments 



Therms. 



Meadow hay 3-44 



Ensiled meadow hay 3. 70 



Hay from irrigated meadows 3. 60 



Broom-corn millet meal 3. 68 



Pumpkins 4- 29 



On the other hand, four experiments upon a bull by Voltz et al. (48), 

 in which the production of methane was likewise computed, gave notably 

 higher figures, viz: 



Metabolizable energy per kilogram of digestible organic matter: Voltz's experiments 



Therms. 

 Mixed ration (hay, straw, malt sprouts, dried brewers' grains, and potato flakes) . 3. 95 



Dried distillery residue (from potatoes) 4. 84 



Palm-nut meal 4- 85 



Beet molasses 4. 36 



The most important factor influencing the metabolizable energy of the 

 digestible organic matter of concentrates seems to be the percentage of 

 fat in the feeding stuff, as appears from a comparison of the data con- 

 tained in Table I, while feeding stuffs exceptionally high in protein have 

 also a high content of metabolizable energy in their digestible matter, as 

 in the case of Kellner and Kohler's wheat gluten. There seems no 

 ob%-ious explanation of the exceptionally high results obtained by Voltz, 

 but it would seem that for the present, with the ordinary dry feeding 

 stuffs or mixtures, the following factors may safely be made the basis 

 for computing approximately the metabolizable energy of feeding stuffs 

 for cattle when their content of digestible organic matter is known or 

 can be estimated. 



