Nov. 4. 1918 Net Energy Values of Alfalfa Hay and Starch 277 



or of digested organic matter was somewhat less on the Hghter rations 

 despite their higher digestibihty. The difference v/ould be still more 

 marked if account were taken of the fact that o-n the lighter rations a 

 larger proportion of the metabolizable energy is accounted for by the heat 

 of fermentation of the carbohydrates. 



The metabolizable energy per kilogram of digested organic matter 

 agrees closely with the results obtained by us * in earlier experiments on 

 roughage and by Kellner ^ in his experiments on starch. 



HEAT EMISSION AND PRODUCTION 



The results of the measurements of heat emission are contained in 

 Table 5 of the Appendix. The heat emission, however, does not usually 

 correspond with the heat production. 



First, any matter gained by the body is raised from the temperature of 

 the calorimeter to the temiperature of the body and a corresponding 

 amount of the heat produced is stored up as heat in this added material. 



Second, a rise in body temperature while the animal is in the calorime- 

 ter likewise absorbs a certain amount of the heat actually produced. 

 Both these amounts must therefore be added to the heat emission to get 

 the real heat production. Of course this correction may be negative — 

 that is, a fall of body temperature or a loss of body weight gives a negative 

 correction — so that in such a case the heat production is less than the heat 

 emission. The corrections due to these two causes are shown in the Ap- 

 pendix, Tables 6 and 7, while Table 8 shows the heat emission, the cor- 

 rections, the heat production as thus computed and also the heat produc- 

 tion as computed in the usual way from the balance of nitrogen and car- 

 bon — that is, by indirect calorimetry. 



CORRECTION FOR STANDING AND LYING 



Standing as compared with lying exerts such a marked influence upon 

 the metabolism of cattle that it is necessary to make a correction for this 

 factor in order to render the different periods of an experiment compara- 

 ble. The heat production has therefore been computed to 12 hours each 

 standing and lying in the manner described in a previous paper.^ On 

 using the same corrections as before for body gain and body temperature 

 the results are as shown in Table XI. 



1 Armsby, H. p., and Fries, J. A. net energy values of feeding stuffs for cattle. In Jour. Agr. 

 Research, v. 3, no. 6, p. 451. 1915- 



ENERGY VALUES OF HOMINY FEED AND MAIZE MEAL FOR CATTLE. 1)1 Jcur. Agr. Research, 



V. lo, no. 12, p. 605. 1917. 



and Bramann, W. W. energy values of red-clover hav and maize meal. In Jour. 



Agr. Research, v. 7, no. 9, p. 382. 



2ARMSDY, H. P. THE nutrition OF FARM animals, p. 301. New Vork, 1917. 



— and Fries, J. A. OP. ciT., 1915, p. 452. 



' Armsby, H. P., and Fries, J. A. op. cit., 1915, p. 454. 



