3 oo 



NUTRITION OF FARM ANIMALS 



materially less than was obtained in Wolff's earlier experiments 

 with hay and about the same as that found by him and by 

 Zuntz and Hagemann for rations containing much grain. 



The following summary of the data regarding the metaboliz- 

 able energy required for maintenance by the horse shows a 

 considerable range of variation which is only partially expli- 

 cable by the varying proportions of grain and roughage con- 

 tained in the rations. 



TABLE 52. MAINTENANCE RATIONS OF THE HORSE 



387. Metabolizable compared with net energy requirement. 



The net energy required for maintenance, as with other ani- 

 mals, equals of course the fasting katabolism. This Zuntz and 

 Hagemann compute, in the manner already described (385) to 

 be 4.1 Therms per thousand pounds live weight. As was 

 there pointed out, however, those of their experiments in which 

 the external temperature was lower or the amount of feed less 

 gave higher results. The latter was also notably the case in 

 earlier experiments in which still lighter rations were fed. 



On the average of the eight most satisfactory experiments out of 

 twelve * on Horse II the total katabolism per day and head was 11.027 

 Therms upon a ration consisting of 3.5 Kgs. of oats, 0.5 of straw and 

 2.5 of hay. Computed in the same manner as in Table 51, the 

 expenditure of energy in the digestion of this ration is equal to 

 3782 Cals., which leaves a remainder of 7244 Cals., equivalent to 

 140.3 Cals., per square centimeter of surface. This is a higher 

 figure than any of those contained in Table 51, although the total 

 katabolism was not notably different. 



1 Landw. Jahrb., 18, i ; 27, Ergzbd. Ill, 356-357- 



