MAINTENANCE THE ENERGY REQUIREMENTS 295 







TABLE 50. MAINTENANCE REQUIREMENTS OF CATTLE AND SHEEP. 

 COMPUTED IN PROPORTION TO BODY SURFACE 



While such a comparison is of course but a rough approxi- 

 mation, it nevertheless seems to show conclusively that the 

 metabolism of the sheep per unit of surface is distinctly lower 

 than that of cattle, so that this animal apparently constitutes 

 an exception to the results computed by E. Voit (345) for 

 several other species. The thick coat of wool, of course, tends 

 to reduce the rate at which heat is lost from the body and it 

 seems at least a plausible conjecture that in the course of or- 

 ganic evolution the intensity of metabolism and the rate of heat 

 radiation may have undergone mutual adjustment. 



The maintenance requirement of the horse 



385. Net energy requirement. Zuntz and Hagemann l 

 have computed the fasting katabolism of the horse from the 

 results of numerous short respiration experiments with the 

 Zuntz type of apparatus (299) by means of a comparison identi- 

 cal in principle with that already described for cattle (374) 

 but carried out by quite a different method, involving numerous 

 estimates and computations. 



They assume, on the basis of experiments on man, that 9 per 

 cent of the metabolizable energy of the digestible nutrients consumed 

 by a horse is converted into heat in the process of digestion, and com- 

 pute from their own experiments that each gram of total crude fiber 

 consumed increases the heat production by 2.086 Cals. additional, 

 exclusive of that due to mastication. For the purpose of computing 

 the fasting energy expenditure, those rest experiments on Horse III 

 in which the feed consisted of oats, hay and straw, are used. On 

 the basis of a number of short respiration experiments made within 

 the first five hours after feeding, the total energy metabolism per day 



1 Landw. Jahrb., 27 (1898), Ergzbd, III, 271-285 and 422-425. 



