THE PRODUCTION VALUES OF FEEDING STUFFS 675 



TABLE 210. COMPUTATION OF NET ENERGY VALUES PER 100 POUNDS 

 ACCORDING TO ARMSBY AND FRIES 



The same method of computation is of course applicable to 

 other species than cattle, so far as the meager data at hand 

 permit. The results of such computations, based upon the 

 average composition and digestibility of American feeding 

 stuffs, are contained in the tables of the Appendix. 



Computation of net energy values for the horse 



775. Zuntz and Hagemann's method. The method em- 

 ployed by Zuntz and Hagemann 1 for computing net energy 

 values for the horse (758) is substantially similar to that just 

 illustrated for cattle. The metabolizable energy is estimated 

 from the digestible nutrients and from it is subtracted the com- 

 puted energy expenditure due to the consumption of the feed. 



776. Metabolizable energy. From the results of five digestion 

 and metabolism experiments on rations of oats, hay and straw in 

 different proportions made at intervals between 1888 and 1891, they 

 compute the metabolizable energy of the total digestible nutrients 

 (including the digested fat multiplied by 2.4) to avenge 3.96 Cals. 

 per gram, corresponding to 3.99 Cals. per gram digestible organic 

 matter as computed by the writer in Table 188 (749). In the 

 respiration experiments, the digestible nutrients were not determined 

 directly but were estimated by combining the results of the same 

 five digestion and metabolism experiments in various ratios according 

 to the proportion of oats, hay and straw consumed. 



777. Increment of heat production: Experiments upon man, 

 made by Magnus-Levy in Zuntz's laboratory, had previously shown 



1 Landw. Jahrb., 27 (1898); Ergzbd. Ill, 211-236, 276-279, 418. 



