MAINTENANCE RATIONS OF HORSES. 



57 



The maintenance requirement as measured by the computed fast- 

 ing katabolism is notably less than that of cattle. The same criti- 

 cisms which have been made of Zuntz and Hagemann's conclusions 

 as regards availability are also applicable, of course, to his compu- 

 tation of the maintenance requirement. 



WOLFF'S INVESTIGATIONS. 



Wolff has also determined by a different method the maintenance 

 ration of the horse in the experiments whose results as regards 

 the available energy of feeds have already been mentioned on page 

 25. As there noted, the amount of work performed by the horse 

 was adjusted so as to be as nearly as possible in equilibrium with 

 the feed consumed. Wolff's experiments were made with a sweep 

 power arranged to serve also as a dynamometer. The actual meas- 

 urements of the work performed, except in the later experiments, 

 proved to be too low ; but Wolff believes them to be relatively correct, 

 so that the ratio between the work as measured and the additional 

 feed required to produce it may still serve as the basis of computation. 



In the experiments of 1877-1886 1 it was found that the work performed in 

 100 revolutions of the dynamometer required the addition to the ration of 

 315 grams of digestible nutrients. It is important to note, however, in view 

 of what follows, that this additional digestible material included no digestible 

 crude fiber — that is, that it was practically derived from the grain added in 

 the periods of heavier work. Subtracting from the total digestible nutrients 

 of the ration, therefore, an amount computed on this basis to be equivalent to 

 the work done leaves-a remainder representing the nutrients required for mainte- 

 nance on the virtual assumption that all the work done was performed at the 

 expense of nutrients derived from the grain. The results of these computa- 

 tions are summarized in the following table : 



Maintenance rations of horses — Wolff, 1877-1886. 



Animal. 



Number 

 of experi- 

 ments. 



Total 

 nutri- 

 ents. 



Nutri- 

 tive 

 ratio. 



Live 

 weight. 



Number 

 of revolu- 

 tions. 



Equiva- 

 lent nutri- 

 ents. 



Mainte- 

 nance 

 ration 

 by differ- 

 ence. 



Horse II: 



1881- 82 



1882- 83 



1883- 84 



Horse III: 



1881- 82 



1882- 83 



1883- 84 



1885 



Average 



4 



Grams. 

 6, 305. 6 



1:5. 79 



Kilos. 

 521 



600 



Grams. 

 1,890 



Grams. 

 4, 416 



7 

 4 



6 



5,831.1 

 6, 748. 3 

 5, 920. 2 



1:6. 64 

 1:6.37 

 1:7.26 



477 



486 

 457 



546 

 662 

 567 



1,720 

 2,085 

 1,786 



4,111 



4,663 

 4, 134 



17 



6,078.4 



1:6. 80 



473 



577 



1,818 



4,260 



6 

 6 

 5 

 4 



5,313.8 

 6,061.3 

 5,734.8 

 5,761.2 



1:7. 16 

 1:6. 88 

 1:7. 55 

 1:7. 57 



454 

 469 

 473 

 473 



404 



683 

 580 

 575 



1,273 

 2,152 

 1,827 

 1,811 



4,041 

 3,909 

 3.908 

 3,050 



21 



5,717.8 



1:7. 29 



467 



501 



1,766 



3,952 



1 Grundlagen fur die rationelle Fiitterung des Pferdes, 1886, 66-155 ; Neue Beitrage ; 

 Landwirtschaftliche Jahrbiicher, vol. 16, Erganzungs Band III, 1-48. 



